diff --git a/assets/js/components/Auth/AdminPasswordPrompt.vue b/assets/js/components/Auth/AdminPasswordPrompt.vue
new file mode 100644
index 000000000..b2a689af2
--- /dev/null
+++ b/assets/js/components/Auth/AdminPasswordPrompt.vue
@@ -0,0 +1,27 @@
+<template>
+	<div class="alert alert-warning mt-4 pb-0" role="alert" data-testid="admin-password-prompt">
+		<p class="fw-bold mb-2">{{ $t("config.adminPassword.title") }}</p>
+		<p>{{ $t("config.adminPassword.description") }}</p>
+		<PasswordInput
+			class="text-body"
+			:password="password"
+			:error="invalid ? $t('config.adminPassword.invalid') : ''"
+			@update:password="$emit('update:password', $event)"
+		/>
+	</div>
+</template>
+
+<script lang="ts">
+import { defineComponent } from "vue";
+import PasswordInput from "./PasswordInput.vue";
+
+export default defineComponent({
+	name: "AdminPasswordPrompt",
+	components: { PasswordInput },
+	props: {
+		password: { type: String, default: "" },
+		invalid: Boolean,
+	},
+	emits: ["update:password"],
+});
+</script>
diff --git a/assets/js/components/Config/DeviceModal/Actions.vue b/assets/js/components/Config/DeviceModal/Actions.vue
index faddd5183..a5fe69235 100644
--- a/assets/js/components/Config/DeviceModal/Actions.vue
+++ b/assets/js/components/Config/DeviceModal/Actions.vue
@@ -1,5 +1,7 @@
 <template>
 	<div>
+		<slot name="before-test"></slot>
+
 		<TestResult
 			v-if="testState"
 			v-bind="testState"
diff --git a/assets/js/components/Config/DeviceModal/DeviceModalBase.vue b/assets/js/components/Config/DeviceModal/DeviceModalBase.vue
index 0cf5c74d8..7b8e6e20d 100644
--- a/assets/js/components/Config/DeviceModal/DeviceModalBase.vue
+++ b/assets/js/components/Config/DeviceModal/DeviceModalBase.vue
@@ -179,6 +179,13 @@
 					@remove="handleRemove"
 					@test="testManually"
 				>
+					<template #before-test>
+						<AdminPasswordPrompt
+							v-if="adminPasswordRequired"
+							v-model:password="adminPasswordValue"
+							:invalid="adminPasswordInvalid"
+						/>
+					</template>
 					<template #after-test>
 						<slot name="after-test" :values="values"></slot>
 					</template>
@@ -207,6 +214,7 @@ import AuthConnectButton from "../AuthConnectButton.vue";
 import { initialTestState, performTest } from "../utils/test";
 import { reportValidityInModal } from "../utils/reportValidityInModal";
 import { initialAuthState, prepareAuthLogin } from "../utils/authProvider";
+import AdminPasswordPrompt from "@/components/Auth/AdminPasswordPrompt.vue";
 import sleep from "@/utils/sleep";
 import { ConfigType } from "@/types/evcc";
 import type { DeviceType, Timeout } from "@/types/evcc";
@@ -223,6 +231,7 @@ import {
 	applyDefaultsFromTemplate,
 	createDeviceUtils,
 	fetchServiceValues,
+	ADMIN_PASSWORD_REQUIRED,
 } from "./index";
 import deepEqual from "@/utils/deepEqual";
 
@@ -244,6 +253,7 @@ export default defineComponent({
 		YamlEntry,
 		AuthCodeDisplay,
 		AuthConnectButton,
+		AdminPasswordPrompt,
 	},
 	props: {
 		deviceType: { type: String as PropType<DeviceType>, required: true },
@@ -313,6 +323,9 @@ export default defineComponent({
 			test: initialTestState(),
 			serviceValues: {} as Record<string, string[]>,
 			serviceValuesTimer: null as Timeout | null,
+			adminPasswordValue: "",
+			adminPasswordRequired: false,
+			adminPasswordInvalid: false,
 		};
 	},
 	computed: {
@@ -546,10 +559,15 @@ export default defineComponent({
 				if (this.test.isError || this.test.isSuccess) {
 					this.test = initialTestState();
 				}
+				this.adminPasswordRequired = false;
+				this.adminPasswordInvalid = false;
 				this.updateServiceValues();
 			},
 			deep: true,
 		},
+		adminPasswordValue() {
+			this.adminPasswordInvalid = false;
+		},
 		authValues: {
 			handler() {
 				if (this.authRequired) {
@@ -699,22 +717,35 @@ export default defineComponent({
 
 			this.saving = true;
 			try {
-				const { name } = await this.device.create(this.apiData, force);
+				const res = await this.device.create(this.apiData, force, this.adminPasswordValue);
+				this.applyAdminPasswordState(res.status);
+				if (res.status === ADMIN_PASSWORD_REQUIRED) {
+					this.saving = false;
+					return;
+				}
 				this.saving = false;
 				this.succeeded = true;
 				await sleep(500);
-				this.$emit("added", name);
-				await closeModal({ action: "added", name });
+				this.$emit("added", res.data.name);
+				await closeModal({ action: "added", name: res.data.name });
 			} catch (e) {
-				handleError(e, "create failed");
 				this.saving = false;
+				handleError(e, "create failed");
 			}
 		},
 		async testManually() {
 			await performTest(this.test, this.testDevice, this.$refs["form"] as HTMLFormElement);
 		},
 		async testDevice() {
-			return this.device.test(this.id, this.apiData);
+			const res = await this.device.test(this.id, this.apiData, this.adminPasswordValue);
+			this.applyAdminPasswordState(res.status);
+			return res;
+		},
+		// reveal the admin password field when required, flag it invalid if a password was already sent
+		applyAdminPasswordState(status: number) {
+			this.adminPasswordRequired = status === ADMIN_PASSWORD_REQUIRED;
+			this.adminPasswordInvalid =
+				status === ADMIN_PASSWORD_REQUIRED && !!this.adminPasswordValue;
 		},
 		async update(force = false) {
 			if (this.test.isUnknown && !force) {
@@ -729,16 +760,26 @@ export default defineComponent({
 			}
 			this.saving = true;
 			try {
-				await this.device.update(this.id!, this.apiData, force);
+				const res = await this.device.update(
+					this.id!,
+					this.apiData,
+					force,
+					this.adminPasswordValue
+				);
+				this.applyAdminPasswordState(res.status);
+				if (res.status === ADMIN_PASSWORD_REQUIRED) {
+					this.saving = false;
+					return;
+				}
 				this.saving = false;
 				this.succeeded = true;
 				await sleep(500);
 				this.$emit("updated");
 				await closeModal({ action: "updated" });
 			} catch (e) {
+				this.saving = false;
 				console.error("update failed", e);
 				handleError(e, "update failed");
-				this.saving = false;
 			}
 		},
 		async remove() {
@@ -752,6 +793,8 @@ export default defineComponent({
 		},
 		handleOpen() {
 			this.isModalVisible = true;
+			this.adminPasswordRequired = false;
+			this.adminPasswordInvalid = false;
 		},
 		handleClose() {
 			this.$emit("close");
diff --git a/assets/js/components/Config/DeviceModal/index.ts b/assets/js/components/Config/DeviceModal/index.ts
index 3f4e16a4e..f57c05bf6 100644
--- a/assets/js/components/Config/DeviceModal/index.ts
+++ b/assets/js/components/Config/DeviceModal/index.ts
@@ -3,6 +3,16 @@ import { ConfigType } from "@/types/evcc";
 import api from "@/api";
 import { extractPlaceholders, replacePlaceholders } from "@/utils/placeholder";
 
+// config write needs the admin password (script plugin)
+export const ADMIN_PASSWORD_REQUIRED = 428;
+
+const allowAdminPasswordRequired = (status: number) =>
+  (status >= 200 && status < 300) || status === ADMIN_PASSWORD_REQUIRED;
+
+function adminPasswordHeader(adminPassword = ""): Record<string, string> {
+  return adminPassword ? { "X-Admin-Password": adminPassword } : {};
+}
+
 export type Product = {
   group: string;
   name: string;
@@ -189,17 +199,25 @@ export const fetchServiceValues = async (
 };
 
 export function createDeviceUtils(deviceType: DeviceType) {
-  function test(id: number | undefined, data: any) {
+  function test(id: number | undefined, data: any, adminPassword = "") {
     let url = `config/test/${deviceType}`;
     if (id !== undefined) {
       url += `/merge/${id}`;
     }
-    return api.post(url, data);
+    const opts = {
+      headers: adminPasswordHeader(adminPassword),
+      validateStatus: allowAdminPasswordRequired,
+    };
+    return api.post(url, data, opts);
   }
 
-  function update(id: number, data: any, force = false) {
-    const params = { force };
-    return api.put(`config/devices/${deviceType}/${id}`, data, { params });
+  function update(id: number, data: any, force = false, adminPassword = "") {
+    const opts = {
+      headers: adminPasswordHeader(adminPassword),
+      validateStatus: allowAdminPasswordRequired,
+      params: { force },
+    };
+    return api.put(`config/devices/${deviceType}/${id}`, data, opts);
   }
 
   function remove(id: number) {
@@ -211,10 +229,13 @@ export function createDeviceUtils(deviceType: DeviceType) {
     return response.data;
   }
 
-  async function create(data: any, force = false) {
-    const params = { force };
-    const response = await api.post(`config/devices/${deviceType}`, data, { params });
-    return response.data;
+  function create(data: any, force = false, adminPassword = "") {
+    const opts = {
+      headers: adminPasswordHeader(adminPassword),
+      validateStatus: allowAdminPasswordRequired,
+      params: { force },
+    };
+    return api.post(`config/devices/${deviceType}`, data, opts);
   }
 
   async function loadProducts(lang?: string, usage?: string) {
diff --git a/assets/js/components/Config/YamlEditor.vue b/assets/js/components/Config/YamlEditor.vue
index 22b7f1560..53ca780a5 100644
--- a/assets/js/components/Config/YamlEditor.vue
+++ b/assets/js/components/Config/YamlEditor.vue
@@ -61,7 +61,6 @@ export default {
 <style scoped>
 .editor {
 	border: 1px solid var(--bs-border-color);
-	min-height: 150px;
 }
 .editor-loading {
 	padding: 0.5rem 0.75rem;
diff --git a/assets/js/components/Config/YamlEditorContainer.vue b/assets/js/components/Config/YamlEditorContainer.vue
index 083246393..cbd93daf4 100644
--- a/assets/js/components/Config/YamlEditorContainer.vue
+++ b/assets/js/components/Config/YamlEditorContainer.vue
@@ -47,17 +47,7 @@ export default {
 </script>
 
 <style scoped>
-@import "../../../css/breakpoints.css";
-
 .editor-container {
-	width: 100%;
 	overflow: hidden;
-	margin: 0 -1rem 0 -1.25rem;
-}
-/* reset margins on lg */
-@media (--lg-and-up) {
-	.editor-container {
-		margin: 0;
-	}
 }
 </style>
diff --git a/assets/js/components/Config/utils/test.ts b/assets/js/components/Config/utils/test.ts
index f6e8d6047..578fd3a21 100644
--- a/assets/js/components/Config/utils/test.ts
+++ b/assets/js/components/Config/utils/test.ts
@@ -1,5 +1,6 @@
 import type { AxiosResponse } from "axios";
 import sleep from "@/utils/sleep";
+import { ADMIN_PASSWORD_REQUIRED } from "../DeviceModal/index";
 import { reportValidityInModal } from "./reportValidityInModal";
 
 export type TestState = {
@@ -36,6 +37,10 @@ export const performTest = async (
   const startTime = Date.now();
   try {
     const res = await api();
+    if (res.status === ADMIN_PASSWORD_REQUIRED) {
+      state.isUnknown = true; // not testable until the admin password is provided
+      return false;
+    }
     state.isError = false;
     state.error = null;
     state.errorLine = null;
diff --git a/docs/agents/api-security.md b/docs/agents/api-security.md
index 519d577c6..ab3b51ca5 100644
--- a/docs/agents/api-security.md
+++ b/docs/agents/api-security.md
@@ -88,11 +88,21 @@ achieves the same effect (the previous key stops working immediately).
 | State / read-only / basic charging control   | Public    |                                    |
 | Set or update admin password                 | Public    | admin password                     |
 | Configuration                                | Secure    |                                    |
+| Configuration embedding a script plugin       | Critical  | api key or admin password          |
 | System: logs, cache, shutdown                | Secure    |                                    |
 | API key status                               | Secure    |                                    |
 | System: backup / restore / reset             | Critical  | api key or admin password          |
 | API key regenerate                           | Critical  | admin password                     |
 
+Device test, create, and update (`/api/config/test/{class}` and `/api/config/devices/{class}`)
+instantiate a config immediately, so a `script` plugin in the payload runs a shell command on the
+server. Because that command could read credentials a session is not otherwise allowed to see (for
+example the contents of the database), these requests are treated as Critical when the config embeds
+a script plugin, at any nesting depth. A session caller must supply the admin password in the
+`X-Admin-Password` header; an API-key caller passes without it. The `go` (yaegi) and `js` (otto)
+plugins are excluded: their interpreters are sandboxed to pure computation and cannot read files,
+spawn processes, or open network connections.
+
 **Public** endpoints accept any caller. **Secure** endpoints require a
 valid session (cookie or API key). **Critical** endpoints require extra
 authentication in the form of an admin password (or, for some, an API
diff --git a/i18n/de.json b/i18n/de.json
index 7d6843cf7..1d62d0407 100644
--- a/i18n/de.json
+++ b/i18n/de.json
@@ -51,6 +51,11 @@
     "hex": "Hex-Farbe"
   },
   "config": {
+    "adminPassword": {
+      "description": "Das Skript-Plugin führt einen Befehl auf Systemebene aus, der mit den Rechten des evcc-Prozesses läuft. Gib dein Administrator-Passwort erneut ein, um fortzufahren.",
+      "invalid": "Ungültiges Passwort. Bitte versuche es erneut.",
+      "title": "Potenziell gefährliche Aktion"
+    },
     "apiKey": {
       "description": "Gibt Skripten und Automatisierungsaufgaben wie geplanten Backups sicheren Zugriff, ohne dein Administrator-Passwort zu teilen.",
       "exampleLabel": "Ausprobieren: Backup mit curl herunterladen",
diff --git a/i18n/en.json b/i18n/en.json
index f304c5f99..df34c3032 100644
--- a/i18n/en.json
+++ b/i18n/en.json
@@ -51,6 +51,11 @@
     "hex": "Hex color"
   },
   "config": {
+    "adminPassword": {
+      "description": "The script plugin executes a system-level command that runs with the permissions of the evcc process. Re-enter your admin password to continue.",
+      "invalid": "Invalid password. Please try again.",
+      "title": "Potentially dangerous operation"
+    },
     "apiKey": {
       "description": "Give scripts and automation tasks like scheduled backups secure access without sharing your admin password.",
       "exampleLabel": "Try it: download a backup with curl",
diff --git a/server/http.go b/server/http.go
index 2956eeccc..546d5bf26 100644
--- a/server/http.go
+++ b/server/http.go
@@ -298,11 +298,11 @@ func (s *HTTPd) RegisterSystemHandler(site *core.Site, pub publisher, cache *uti
 			"devicestatus":       {"GET", "/devices/{class:[a-z]+}/{name:[a-zA-Z0-9_.:-]+}/status", deviceStatusHandler},
 			"dirty":              {"GET", "/dirty", getHandler(ConfigDirty)},
 			"evccyaml":           {"GET", "/evcc.yaml", configYamlHandler(configFile)},
-			"newdevice":          {"POST", "/devices/{class:[a-z]+}", newDeviceHandler},
-			"updatedevice":       {"PUT", "/devices/{class:[a-z]+}/{id:[0-9.]+}", updateDeviceHandler},
+			"newdevice":          {"POST", "/devices/{class:[a-z]+}", newDeviceHandler(auth)},
+			"updatedevice":       {"PUT", "/devices/{class:[a-z]+}/{id:[0-9.]+}", updateDeviceHandler(auth)},
 			"deletedevice":       {"DELETE", "/devices/{class:[a-z]+}/{id:[0-9.]+}", deleteDeviceHandler(site)},
-			"testconfig":         {"POST", "/test/{class:[a-z]+}", testConfigHandler},
-			"testmerged":         {"POST", "/test/{class:[a-z]+}/merge/{id:[0-9.]+}", testConfigHandler},
+			"testconfig":         {"POST", "/test/{class:[a-z]+}", testConfigHandler(auth)},
+			"testmerged":         {"POST", "/test/{class:[a-z]+}/merge/{id:[0-9.]+}", testConfigHandler(auth)},
 			"interval":           {"POST", "/interval/{value:[0-9.]+}", settingsSetDurationHandler(keys.Interval, pub)},
 			"updatesponsortoken": {"POST", "/sponsortoken", updateSponsortokenHandler(pub)},
 			"deletesponsortoken": {"DELETE", "/sponsortoken", deleteSponsorTokenHandler(pub)},
diff --git a/server/http_auth.go b/server/http_auth.go
index e05071179..9aaeae36b 100644
--- a/server/http_auth.go
+++ b/server/http_auth.go
@@ -2,6 +2,7 @@ package server
 
 import (
 	"encoding/json"
+	"errors"
 	"net/http"
 	"strings"
 	"time"
@@ -241,6 +242,21 @@ func regenerateApiKeyHandler(authObject auth.Auth) http.HandlerFunc {
 	}
 }
 
+// requireCriticalConfigAuth guards script-plugin configs: API key passes; session users must supply the admin password.
+func requireCriticalConfigAuth(w http.ResponseWriter, r *http.Request, authObject auth.Auth, req configReq) bool {
+	if authObject.GetAuthMode() == auth.Disabled || !configHasCriticalPlugin(req) {
+		return true
+	}
+	if key := apiKeyFromRequest(r); key != "" && authObject.ValidateApiKey(key) {
+		return true
+	}
+	if !authObject.IsAdminPasswordValid(r.Header.Get("X-Admin-Password")) {
+		jsonError(w, http.StatusPreconditionRequired, errors.New("admin password required"))
+		return false
+	}
+	return true
+}
+
 // ensureDbAuth guards /db/ endpoints: API key Bearer passes directly;
 // session users must also supply the admin password in X-Admin-Password header.
 func ensureDbAuth(authObject auth.Auth) mux.MiddlewareFunc {
diff --git a/server/http_auth_test.go b/server/http_auth_test.go
new file mode 100644
index 000000000..d91b0718d
--- /dev/null
+++ b/server/http_auth_test.go
@@ -0,0 +1,74 @@
+package server
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"testing"
+	"time"
+
+	"github.com/evcc-io/evcc/util/auth"
+	"github.com/stretchr/testify/assert"
+)
+
+// fakeAuth is a minimal auth.Auth stub for gate tests.
+type fakeAuth struct {
+	mode     auth.AuthMode
+	password string
+	apiKey   string
+}
+
+func (f fakeAuth) GetAuthMode() auth.AuthMode                     { return f.mode }
+func (f fakeAuth) IsAdminPasswordValid(pw string) bool            { return pw != "" && pw == f.password }
+func (f fakeAuth) ValidateApiKey(key string) bool                 { return key != "" && key == f.apiKey }
+func (f fakeAuth) SetAuthMode(auth.AuthMode)                      {}
+func (f fakeAuth) RemoveAdminPassword()                           {}
+func (f fakeAuth) SetAdminPassword(string) error                  { return nil }
+func (f fakeAuth) GenerateJwtToken(time.Duration) (string, error) { return "", nil }
+func (f fakeAuth) ValidateJwtToken(string) bool                   { return true }
+func (f fakeAuth) IsAdminPasswordConfigured() bool                { return f.password != "" }
+func (f fakeAuth) SetApiKey() (string, error)                     { return "", nil }
+func (f fakeAuth) IsApiKeyConfigured() bool                       { return f.apiKey != "" }
+
+func TestRequireCriticalConfig(t *testing.T) {
+	const pw = "secret"
+	const key = "evcc_token"
+	scriptReq := configReq{Yaml: "power:\n  source: script\n  cmd: echo 1"}
+	benignReq := configReq{Yaml: "power:\n  source: http\n  uri: http://localhost"}
+
+	base := fakeAuth{mode: auth.Enabled, password: pw, apiKey: key}
+
+	tc := []struct {
+		name   string
+		req    configReq
+		header map[string]string
+		mode   auth.AuthMode
+		ok     bool
+	}{
+		{"no critical plugin passes", benignReq, nil, auth.Enabled, true},
+		{"disabled mode passes", scriptReq, nil, auth.Disabled, true},
+		{"session without password rejected", scriptReq, nil, auth.Enabled, false},
+		{"session with wrong password rejected", scriptReq, map[string]string{"X-Admin-Password": "nope"}, auth.Enabled, false},
+		{"session with valid password passes", scriptReq, map[string]string{"X-Admin-Password": pw}, auth.Enabled, true},
+		{"valid api key passes without password", scriptReq, map[string]string{"Authorization": "Bearer " + key}, auth.Enabled, true},
+	}
+
+	for _, tc := range tc {
+		t.Run(tc.name, func(t *testing.T) {
+			a := base
+			a.mode = tc.mode
+
+			r := httptest.NewRequest(http.MethodPost, "/api/config/test/meter", nil)
+			for k, v := range tc.header {
+				r.Header.Set(k, v)
+			}
+			w := httptest.NewRecorder()
+
+			ok := requireCriticalConfigAuth(w, r, a, tc.req)
+
+			assert.Equal(t, tc.ok, ok)
+			if !tc.ok {
+				assert.Equal(t, http.StatusPreconditionRequired, w.Code)
+			}
+		})
+	}
+}
diff --git a/server/http_config_device_handler.go b/server/http_config_device_handler.go
index 67aeed82c..b92e85ef1 100644
--- a/server/http_config_device_handler.go
+++ b/server/http_config_device_handler.go
@@ -21,6 +21,7 @@ import (
 	"github.com/evcc-io/evcc/meter"
 	"github.com/evcc-io/evcc/server/db/settings"
 	"github.com/evcc-io/evcc/tariff"
+	"github.com/evcc-io/evcc/util/auth"
 	"github.com/evcc-io/evcc/util/config"
 	"github.com/evcc-io/evcc/util/templates"
 	"github.com/evcc-io/evcc/vehicle"
@@ -308,66 +309,72 @@ func newDevice[T any](ctx context.Context, class templates.Class, req configReq,
 }
 
 // newDeviceHandler creates a new device by class
-func newDeviceHandler(w http.ResponseWriter, r *http.Request) {
-	vars := mux.Vars(r)
+func newDeviceHandler(authObject auth.Auth) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		vars := mux.Vars(r)
 
-	class, err := templates.ClassString(vars["class"])
-	if err != nil {
-		jsonError(w, http.StatusBadRequest, err)
-		return
+		class, err := templates.ClassString(vars["class"])
+		if err != nil {
+			jsonError(w, http.StatusBadRequest, err)
+			return
+		}
+
+		req, err := decodeDeviceConfig(r.Body)
+		if err != nil {
+			jsonError(w, http.StatusBadRequest, err)
+			return
+		}
+
+		if !requireCriticalConfigAuth(w, r, authObject, req) {
+			return
+		}
+
+		var conf *config.Config
+		ctx, cancel, done := startDeviceTimeout()
+
+		force := r.URL.Query().Get("force") == "true"
+
+		switch class {
+		case templates.Charger:
+			conf, err = newDevice(ctx, class, req, charger.NewFromConfig, config.Chargers(), force)
+
+		case templates.Meter:
+			conf, err = newDevice(ctx, class, req, meter.NewFromConfig, config.Meters(), force)
+
+		case templates.Vehicle:
+			conf, err = newDevice(ctx, class, req, vehicle.NewFromConfig, config.Vehicles(), force)
+
+		case templates.Circuit:
+			conf, err = newDevice(ctx, class, req, circuit.NewFromConfig, config.Circuits(), force)
+
+		case templates.Tariff:
+			conf, err = newDevice(ctx, class, req, tariff.NewFromConfig, config.Tariffs(), force)
+
+		case templates.Messenger:
+			conf, err = newDevice(ctx, class, req, messenger.NewFromConfig, config.Messengers(), force)
+		}
+
+		if err != nil {
+			cancel()
+			jsonError(w, http.StatusBadRequest, err)
+			return
+		}
+
+		// prevent context from being cancelled
+		close(done)
+
+		setConfigDirty()
+
+		res := struct {
+			ID   int    `json:"id"`
+			Name string `json:"name"`
+		}{
+			ID:   conf.ID,
+			Name: config.NameForID(conf.ID),
+		}
+
+		jsonWrite(w, res)
 	}
-
-	req, err := decodeDeviceConfig(r.Body)
-	if err != nil {
-		jsonError(w, http.StatusBadRequest, err)
-		return
-	}
-
-	var conf *config.Config
-	ctx, cancel, done := startDeviceTimeout()
-
-	force := r.URL.Query().Get("force") == "true"
-
-	switch class {
-	case templates.Charger:
-		conf, err = newDevice(ctx, class, req, charger.NewFromConfig, config.Chargers(), force)
-
-	case templates.Meter:
-		conf, err = newDevice(ctx, class, req, meter.NewFromConfig, config.Meters(), force)
-
-	case templates.Vehicle:
-		conf, err = newDevice(ctx, class, req, vehicle.NewFromConfig, config.Vehicles(), force)
-
-	case templates.Circuit:
-		conf, err = newDevice(ctx, class, req, circuit.NewFromConfig, config.Circuits(), force)
-
-	case templates.Tariff:
-		conf, err = newDevice(ctx, class, req, tariff.NewFromConfig, config.Tariffs(), force)
-
-	case templates.Messenger:
-		conf, err = newDevice(ctx, class, req, messenger.NewFromConfig, config.Messengers(), force)
-	}
-
-	if err != nil {
-		cancel()
-		jsonError(w, http.StatusBadRequest, err)
-		return
-	}
-
-	// prevent context from being cancelled
-	close(done)
-
-	setConfigDirty()
-
-	res := struct {
-		ID   int    `json:"id"`
-		Name string `json:"name"`
-	}{
-		ID:   conf.ID,
-		Name: config.NameForID(conf.ID),
-	}
-
-	jsonWrite(w, res)
 }
 
 func updateDevice[T any](ctx context.Context, id int, class templates.Class, req configReq, newFromConf newFromConfFunc[T], h config.Handler[T], force bool) error {
@@ -388,69 +395,75 @@ func updateDevice[T any](ctx context.Context, id int, class templates.Class, req
 }
 
 // updateDeviceHandler updates database device's configuration by class
-func updateDeviceHandler(w http.ResponseWriter, r *http.Request) {
-	vars := mux.Vars(r)
+func updateDeviceHandler(authObject auth.Auth) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		vars := mux.Vars(r)
 
-	class, err := templates.ClassString(vars["class"])
-	if err != nil {
-		jsonError(w, http.StatusBadRequest, err)
-		return
+		class, err := templates.ClassString(vars["class"])
+		if err != nil {
+			jsonError(w, http.StatusBadRequest, err)
+			return
+		}
+
+		id, err := strconv.Atoi(vars["id"])
+		if err != nil {
+			jsonError(w, http.StatusBadRequest, err)
+			return
+		}
+
+		req, err := decodeDeviceConfig(r.Body)
+		if err != nil {
+			jsonError(w, http.StatusBadRequest, err)
+			return
+		}
+
+		if !requireCriticalConfigAuth(w, r, authObject, req) {
+			return
+		}
+
+		ctx, cancel, done := startDeviceTimeout()
+
+		force := r.URL.Query().Get("force") == "true"
+
+		switch class {
+		case templates.Charger:
+			err = updateDevice(ctx, id, class, req, charger.NewFromConfig, config.Chargers(), force)
+
+		case templates.Meter:
+			err = updateDevice(ctx, id, class, req, meter.NewFromConfig, config.Meters(), force)
+
+		case templates.Vehicle:
+			err = updateDevice(ctx, id, class, req, vehicle.NewFromConfig, config.Vehicles(), force)
+
+		case templates.Circuit:
+			err = updateDevice(ctx, id, class, req, circuit.NewFromConfig, config.Circuits(), force)
+
+		case templates.Tariff:
+			err = updateDevice(ctx, id, class, req, tariff.NewFromConfig, config.Tariffs(), force)
+
+		case templates.Messenger:
+			err = updateDevice(ctx, id, class, req, messenger.NewFromConfig, config.Messengers(), force)
+		}
+
+		setConfigDirty()
+
+		if err != nil {
+			cancel()
+			jsonError(w, http.StatusBadRequest, err)
+			return
+		}
+
+		// prevent context from being cancelled
+		close(done)
+
+		res := struct {
+			ID int `json:"id"`
+		}{
+			ID: id,
+		}
+
+		jsonWrite(w, res)
 	}
-
-	id, err := strconv.Atoi(vars["id"])
-	if err != nil {
-		jsonError(w, http.StatusBadRequest, err)
-		return
-	}
-
-	req, err := decodeDeviceConfig(r.Body)
-	if err != nil {
-		jsonError(w, http.StatusBadRequest, err)
-		return
-	}
-
-	ctx, cancel, done := startDeviceTimeout()
-
-	force := r.URL.Query().Get("force") == "true"
-
-	switch class {
-	case templates.Charger:
-		err = updateDevice(ctx, id, class, req, charger.NewFromConfig, config.Chargers(), force)
-
-	case templates.Meter:
-		err = updateDevice(ctx, id, class, req, meter.NewFromConfig, config.Meters(), force)
-
-	case templates.Vehicle:
-		err = updateDevice(ctx, id, class, req, vehicle.NewFromConfig, config.Vehicles(), force)
-
-	case templates.Circuit:
-		err = updateDevice(ctx, id, class, req, circuit.NewFromConfig, config.Circuits(), force)
-
-	case templates.Tariff:
-		err = updateDevice(ctx, id, class, req, tariff.NewFromConfig, config.Tariffs(), force)
-
-	case templates.Messenger:
-		err = updateDevice(ctx, id, class, req, messenger.NewFromConfig, config.Messengers(), force)
-	}
-
-	setConfigDirty()
-
-	if err != nil {
-		cancel()
-		jsonError(w, http.StatusBadRequest, err)
-		return
-	}
-
-	// prevent context from being cancelled
-	close(done)
-
-	res := struct {
-		ID int `json:"id"`
-	}{
-		ID: id,
-	}
-
-	jsonWrite(w, res)
 }
 
 func configurableDevice[T any](name string, h config.Handler[T]) (config.ConfigurableDevice[T], error) {
@@ -644,67 +657,73 @@ func testConfig[T any](ctx context.Context, id int, class templates.Class, req c
 }
 
 // testConfigHandler tests a configuration by class
-func testConfigHandler(w http.ResponseWriter, r *http.Request) {
-	vars := mux.Vars(r)
+func testConfigHandler(authObject auth.Auth) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		vars := mux.Vars(r)
 
-	class, err := templates.ClassString(vars["class"])
-	if err != nil {
-		jsonError(w, http.StatusBadRequest, err)
-		return
-	}
-
-	var id int
-	if vars["id"] != "" {
-		// test existing device with updated config
-		id, err = strconv.Atoi(vars["id"])
+		class, err := templates.ClassString(vars["class"])
 		if err != nil {
 			jsonError(w, http.StatusBadRequest, err)
 			return
 		}
+
+		var id int
+		if vars["id"] != "" {
+			// test existing device with updated config
+			id, err = strconv.Atoi(vars["id"])
+			if err != nil {
+				jsonError(w, http.StatusBadRequest, err)
+				return
+			}
+		}
+
+		req, err := decodeDeviceConfig(r.Body)
+		if err != nil {
+			jsonError(w, http.StatusBadRequest, err)
+			return
+		}
+
+		if !requireCriticalConfigAuth(w, r, authObject, req) {
+			return
+		}
+
+		var instance any
+		ctx, cancel, done := startDeviceTimeout()
+
+		switch class {
+		case templates.Charger:
+			instance, err = testConfig(ctx, id, class, req, charger.NewFromConfig, config.Chargers())
+
+		case templates.Meter:
+			instance, err = testConfig(ctx, id, class, req, meter.NewFromConfig, config.Meters())
+
+		case templates.Vehicle:
+			instance, err = testConfig(ctx, id, class, req, vehicle.NewFromConfig, config.Vehicles())
+
+		case templates.Circuit:
+			instance, err = testConfig(ctx, id, class, req, circuit.NewFromConfig, config.Circuits())
+
+		case templates.Tariff:
+			instance, err = testConfig(ctx, id, class, req, tariff.NewFromConfig, config.Tariffs())
+
+		case templates.Messenger:
+			instance, err = testConfig(ctx, id, class, req, messenger.NewFromConfig, config.Messengers())
+		}
+
+		if err != nil {
+			cancel()
+			jsonError(w, http.StatusBadRequest, err)
+			return
+		}
+
+		// prevent context from being cancelled during test
+		close(done)
+		defer cancel()
+
+		// bound the value-probe phase so a blocking getter cannot stall the response
+		probeCtx, probeCancel := context.WithTimeout(r.Context(), 10*time.Second)
+		defer probeCancel()
+
+		jsonWrite(w, testInstance(probeCtx, instance))
 	}
-
-	req, err := decodeDeviceConfig(r.Body)
-	if err != nil {
-		jsonError(w, http.StatusBadRequest, err)
-		return
-	}
-
-	var instance any
-	ctx, cancel, done := startDeviceTimeout()
-
-	switch class {
-	case templates.Charger:
-		instance, err = testConfig(ctx, id, class, req, charger.NewFromConfig, config.Chargers())
-
-	case templates.Meter:
-		instance, err = testConfig(ctx, id, class, req, meter.NewFromConfig, config.Meters())
-
-	case templates.Vehicle:
-		instance, err = testConfig(ctx, id, class, req, vehicle.NewFromConfig, config.Vehicles())
-
-	case templates.Circuit:
-		instance, err = testConfig(ctx, id, class, req, circuit.NewFromConfig, config.Circuits())
-
-	case templates.Tariff:
-		instance, err = testConfig(ctx, id, class, req, tariff.NewFromConfig, config.Tariffs())
-
-	case templates.Messenger:
-		instance, err = testConfig(ctx, id, class, req, messenger.NewFromConfig, config.Messengers())
-	}
-
-	if err != nil {
-		cancel()
-		jsonError(w, http.StatusBadRequest, err)
-		return
-	}
-
-	// prevent context from being cancelled during test
-	close(done)
-	defer cancel()
-
-	// bound the value-probe phase so a blocking getter cannot stall the response
-	probeCtx, probeCancel := context.WithTimeout(r.Context(), 10*time.Second)
-	defer probeCancel()
-
-	jsonWrite(w, testInstance(probeCtx, instance))
 }
diff --git a/server/http_config_helper.go b/server/http_config_helper.go
index ae26bb4c1..e15e4e567 100644
--- a/server/http_config_helper.go
+++ b/server/http_config_helper.go
@@ -528,6 +528,38 @@ func (maskedTransformer) Transformer(typ reflect.Type) func(dst, src reflect.Val
 	}
 }
 
+var criticalPluginSources = []string{"script"}
+
+func configHasCriticalPlugin(req configReq) bool {
+	if req.Yaml != "" {
+		var m map[string]any
+		if err := yaml.Unmarshal([]byte(req.Yaml), &m); err != nil {
+			return false // malformed yaml already rejected by decodeDeviceConfig
+		}
+		return valueHasCriticalSource(m)
+	}
+	return valueHasCriticalSource(req.Other)
+}
+
+func valueHasCriticalSource(v any) bool {
+	switch t := v.(type) {
+	case map[string]any:
+		for k, val := range t {
+			if strings.EqualFold(k, "source") {
+				if s, ok := val.(string); ok && slices.Contains(criticalPluginSources, strings.ToLower(strings.TrimSpace(s))) {
+					return true
+				}
+			}
+			if valueHasCriticalSource(val) {
+				return true
+			}
+		}
+	case []any:
+		return slices.ContainsFunc(t, valueHasCriticalSource)
+	}
+	return false
+}
+
 // decodeDeviceConfig extracts device configuration and yaml details
 func decodeDeviceConfig(r io.Reader) (configReq, error) {
 	var res configReq
diff --git a/server/http_config_helper_test.go b/server/http_config_helper_test.go
index bbc3ade09..942717448 100644
--- a/server/http_config_helper_test.go
+++ b/server/http_config_helper_test.go
@@ -210,6 +210,38 @@ func TestMergeMaskedFiltersBehavior(t *testing.T) {
 	assert.NotContains(t, result, "outdatedField")
 }
 
+func TestConfigHasCriticalPlugin(t *testing.T) {
+	tc := []struct {
+		name string
+		yaml string
+		want bool
+	}{
+		{"script top level", "power:\n  source: script\n  cmd: echo 1", true},
+		{"script case insensitive", "power:\n  Source: SCRIPT\n  cmd: echo 1", true},
+		{"script nested in calc", "power:\n  source: calc\n  add:\n    - source: const\n      value: 1\n    - source: script\n      cmd: echo 1", true},
+		{"script nested in sequence set", "power:\n  source: sequence\n  set:\n    - source: script\n      cmd: echo 1", true},
+		{"script nested in js transformation", "power:\n  source: js\n  script: x\n  in:\n    - name: x\n      type: float\n      source: script\n      cmd: echo 1", true},
+		{"js without script", "power:\n  source: js\n  script: \"x = 1\"", false},
+		{"go without script", "power:\n  source: go\n  script: \"return 1\"", false},
+		{"http without script", "power:\n  source: http\n  uri: http://localhost", false},
+		{"plain template", "power: 100", false},
+	}
+
+	for _, tc := range tc {
+		t.Run(tc.name, func(t *testing.T) {
+			assert.Equal(t, tc.want, configHasCriticalPlugin(configReq{Yaml: tc.yaml}))
+		})
+	}
+
+	// non-yaml custom config carried in Other
+	assert.True(t, configHasCriticalPlugin(configReq{
+		Other: map[string]any{"power": map[string]any{"source": "script", "cmd": "echo 1"}},
+	}))
+	assert.False(t, configHasCriticalPlugin(configReq{
+		Other: map[string]any{"template": "tesla"},
+	}))
+}
+
 func TestFilterValidTemplateParams(t *testing.T) {
 	conf := map[string]any{
 		"template":      "generic",
diff --git a/tests/config-script-plugin.spec.ts b/tests/config-script-plugin.spec.ts
new file mode 100644
index 000000000..bfcc7f9da
--- /dev/null
+++ b/tests/config-script-plugin.spec.ts
@@ -0,0 +1,107 @@
+import { test, expect, type Page } from "@playwright/test";
+import { start, stop, baseUrl } from "./evcc";
+import { expectModalVisible, expectModalHidden, editorClear, editorPaste } from "./utils";
+
+test.use({ baseURL: baseUrl() });
+
+test.afterEach(async () => {
+  await stop();
+});
+
+const SCRIPT_YAML = `power:
+  source: script
+  cmd: echo 9999`;
+
+const UPDATED_YAML = `power:
+  source: script
+  cmd: echo 8888`;
+
+async function login(page: Page) {
+  const loginModal = page.getByTestId("login-modal");
+  await expectModalVisible(loginModal);
+  await loginModal.getByLabel("Administrator Password").fill("secret");
+  await loginModal.getByRole("button", { name: "Login" }).click();
+  await expectModalHidden(loginModal);
+}
+
+async function addCustomGridMeter(page: Page, yaml: string) {
+  await page.getByRole("button", { name: "Add grid meter" }).click();
+  const modal = page.getByTestId("meter-modal");
+  await expectModalVisible(modal);
+  await modal.getByLabel("Manufacturer").selectOption("User-defined device");
+  const editor = modal.getByTestId("yaml-editor");
+  await expect(editor).toBeVisible();
+  await editorClear(editor);
+  await editorPaste(editor, page, yaml);
+  return modal;
+}
+
+test.describe("script plugin requires admin password", async () => {
+  test("caches password across validate and create", async ({ page }) => {
+    await start(undefined, "password.sql", "");
+    await page.goto("/#/config");
+    await login(page);
+
+    const meterModal = await addCustomGridMeter(page, SCRIPT_YAML);
+    const prompt = meterModal.getByTestId("admin-password-prompt");
+    const validate = meterModal.getByTestId("test-result").getByRole("link", { name: "validate" });
+
+    // validate without password reveals the field
+    await validate.click();
+    await expect(prompt).toBeVisible();
+
+    // editing the config hides the field again
+    await editorClear(meterModal.getByTestId("yaml-editor"));
+    await editorPaste(meterModal.getByTestId("yaml-editor"), page, SCRIPT_YAML);
+    await expect(prompt).not.toBeVisible();
+
+    // wrong password keeps the field with an invalid hint
+    await validate.click();
+    await expect(prompt).toBeVisible();
+    await prompt.getByLabel("Administrator Password").fill("wrong");
+    await validate.click();
+    await expect(prompt.getByText("Invalid password. Please try again.")).toBeVisible();
+
+    // correct password validates and hides the field
+    await prompt.getByLabel("Administrator Password").fill("secret");
+    await validate.click();
+    await expect(meterModal.getByTestId("test-result")).toContainText("Status: successful");
+    await expect(prompt).not.toBeVisible();
+
+    // save reuses the cached password, no field reappears
+    await meterModal.getByRole("button", { name: "Save" }).click();
+    await expect(prompt).not.toBeVisible();
+    await expectModalHidden(meterModal);
+    await expect(page.getByTestId("grid")).toBeVisible();
+  });
+
+  test("re-prompts on update after reload", async ({ page }) => {
+    await start(undefined, "password.sql", "");
+    await page.goto("/#/config");
+    await login(page);
+
+    // create a script meter (enter the password once)
+    const meterModal = await addCustomGridMeter(page, SCRIPT_YAML);
+    const prompt = meterModal.getByTestId("admin-password-prompt");
+    await meterModal.getByRole("button", { name: "Save" }).click();
+    await expect(prompt).toBeVisible();
+    await prompt.getByLabel("Administrator Password").fill("secret");
+    await meterModal.getByRole("button", { name: "Save" }).click();
+    await expectModalHidden(meterModal);
+    await expect(page.getByTestId("grid")).toBeVisible();
+
+    // reload drops the cached password
+    await page.reload();
+
+    // editing and saving the existing device prompts again
+    await page.getByTestId("grid").getByRole("button", { name: "edit" }).click();
+    await expectModalVisible(meterModal);
+    await editorClear(meterModal.getByTestId("yaml-editor"));
+    await editorPaste(meterModal.getByTestId("yaml-editor"), page, UPDATED_YAML);
+    await meterModal.getByRole("button", { name: "Save" }).click();
+    await expect(prompt).toBeVisible();
+    await prompt.getByLabel("Administrator Password").fill("secret");
+    await meterModal.getByRole("button", { name: "Save" }).click();
+    await expectModalHidden(meterModal);
+  });
+});