diff --git a/modules/templates/helper.go b/modules/templates/helper.go
index f071353bfad..ae7f3636a6d 100644
--- a/modules/templates/helper.go
+++ b/modules/templates/helper.go
@@ -96,9 +96,6 @@ func newFuncMapWebPage() template.FuncMap {
 		"AllowedReactions": func() []string {
 			return setting.UI.Reactions
 		},
-		"CustomEmojis": func() map[string]string {
-			return setting.UI.CustomEmojisMap
-		},
 		"MetaAuthor": func() string {
 			return setting.UI.Meta.Author
 		},
@@ -114,16 +111,6 @@ func newFuncMapWebPage() template.FuncMap {
 		"DisableWebhooks": func() bool {
 			return setting.DisableWebhooks
 		},
-		"NotificationSettings": func() map[string]any {
-			return map[string]any{
-				"MinTimeout":  int(setting.UI.Notification.MinTimeout / time.Millisecond),
-				"TimeoutStep": int(setting.UI.Notification.TimeoutStep / time.Millisecond),
-				"MaxTimeout":  int(setting.UI.Notification.MaxTimeout / time.Millisecond),
-			}
-		},
-		"MermaidMaxSourceCharacters": func() int {
-			return setting.MermaidMaxSourceCharacters
-		},
 
 		// -----------------------------------------------------------------
 		// render
diff --git a/services/context/context.go b/services/context/context.go
index f13d51c55f1..99e40ea72e6 100644
--- a/services/context/context.go
+++ b/services/context/context.go
@@ -46,8 +46,11 @@ type Context struct {
 
 	TemplateContext TemplateContext
 
-	Render   Render
-	PageData map[string]any // data used by JavaScript modules in one page, it's `window.config.pageData`
+	Render Render
+
+	// PageData is used by JavaScript modules, it is `window.config.pageData`.
+	// Deprecated: it was introduced for refactoring some legacy JS code, it should not be used in new code anymore.
+	PageData map[string]any
 
 	Cache   cache.StringCache
 	Flash   *middleware.Flash
diff --git a/services/context/context_template.go b/services/context/context_template.go
index b4775171eb9..2d990b44add 100644
--- a/services/context/context_template.go
+++ b/services/context/context_template.go
@@ -13,11 +13,11 @@ import (
 	"time"
 
 	user_model "gitea.dev/models/user"
-	"gitea.dev/modules/htmlutil"
 	"gitea.dev/modules/httplib"
 	"gitea.dev/modules/public"
 	"gitea.dev/modules/reqctx"
 	"gitea.dev/modules/setting"
+	"gitea.dev/modules/translation"
 	"gitea.dev/modules/web/middleware"
 	"gitea.dev/services/webtheme"
 )
@@ -148,5 +148,41 @@ func (c TemplateContext) HeadMetaContentSecurityPolicy() template.HTML {
 	if csp == "" {
 		return ""
 	}
-	return htmlutil.HTMLFormat(`<meta http-equiv="Content-Security-Policy" content="%s">`, csp)
+	return template.HTML(`<meta http-equiv="Content-Security-Policy" content="` + csp + `">`)
+}
+
+func (c TemplateContext) WindowConfig() map[string]any {
+	locale := c["Locale"].(translation.Locale) //nolint:forcetypeassert // must exist
+	return map[string]any{
+		"appUrl":                     c.AppFullLink("/"),
+		"appSubUrl":                  setting.AppSubURL,
+		"assetUrlPrefix":             setting.StaticURLPrefix + "/assets",
+		"runModeIsProd":              setting.IsProd,
+		"customEmojis":               setting.UI.CustomEmojisMap,
+		"pageData":                   c.parentContext().GetData()["PageData"],
+		"enableTimeTracking":         setting.Service.EnableTimetracking,
+		"mermaidMaxSourceCharacters": setting.MermaidMaxSourceCharacters,
+		"sharedWorkerUri":            public.AssetURI("web_src/js/user-events.sharedworker.ts"),
+		"notificationSettings": map[string]any{
+			"MinTimeout":  int(setting.UI.Notification.MinTimeout / time.Millisecond),
+			"TimeoutStep": int(setting.UI.Notification.TimeoutStep / time.Millisecond),
+			"MaxTimeout":  int(setting.UI.Notification.MaxTimeout / time.Millisecond),
+		},
+		// This global i18n object should only contain general texts.
+		// for specialized texts, it should be provided inside the related modules by:
+		// (1) API response (2) HTML data-attribute (3) PageData
+		//
+		// Maybe (if really needed) in the future we can introduce versioned frontend i18n data,
+		// make frontend cache i18n data in local storage and only update when the version is changed,
+		// then we can fill more keys here.
+		"i18n": map[string]any{
+			"error_occurred":   locale.Tr("error.occurred"),
+			"remove_label_str": locale.Tr("remove_label_str"),
+			"modal_confirm":    locale.Tr("modal.confirm"),
+			"modal_cancel":     locale.Tr("modal.cancel"),
+			"more_items":       locale.Tr("more_items"),
+			"copy_success":     locale.Tr("copy_success"),
+			"copy_error":       locale.Tr("copy_error"),
+		},
+	}
 }
diff --git a/services/context/context_test.go b/services/context/context_test.go
index f6e34619761..8e56007347c 100644
--- a/services/context/context_test.go
+++ b/services/context/context_test.go
@@ -7,6 +7,7 @@ import (
 	"net/http"
 	"net/http/httptest"
 	"net/url"
+	"strings"
 	"testing"
 
 	"gitea.dev/modules/reqctx"
@@ -64,3 +65,12 @@ func TestAppFullLink(t *testing.T) {
 	assert.Equal(t, "https://gitea.example.com/sub/user/repo", string(tmplCtx.AppFullLink("user/repo")))
 	assert.Equal(t, "https://gitea.example.com/sub/user/repo", string(tmplCtx.AppFullLink("/user/repo")))
 }
+
+func TestHeadMetaContentSecurityPolicy(t *testing.T) {
+	tmplCtx := NewTemplateContext(reqctx.NewRequestContextForTest(t), nil)
+	nonce := tmplCtx.CspScriptNonce()
+	assert.Equal(t, `<meta http-equiv="Content-Security-Policy" content="default-src * data: blob:;script-src * 'nonce-`+nonce+`';style-src * 'unsafe-inline';">`, string(tmplCtx.HeadMetaContentSecurityPolicy()))
+	assert.False(t, strings.ContainsAny(WebContentSecurityPolicy(nonce), `"<>&`))
+	defer test.MockVariableValue(&setting.Security.ContentSecurityPolicyGeneral, "unset")()
+	assert.Empty(t, tmplCtx.HeadMetaContentSecurityPolicy())
+}
diff --git a/templates/base/head_script.tmpl b/templates/base/head_script.tmpl
index 7a918d8bdb1..d1605e97e72 100644
--- a/templates/base/head_script.tmpl
+++ b/templates/base/head_script.tmpl
@@ -6,29 +6,6 @@ If you introduce mistakes in it, Gitea JavaScript code wouldn't run correctly.
 	{{/* before our JS code gets loaded, use arrays to store errors, then the arrays will be switched to our error handler later */}}
 	window.addEventListener('error', function(e) {window._globalHandlerErrors=window._globalHandlerErrors||[]; window._globalHandlerErrors.push(e);});
 	window.addEventListener('unhandledrejection', function(e) {window._globalHandlerErrors=window._globalHandlerErrors||[]; window._globalHandlerErrors.push(e);});
-	window.config = {
-		appUrl: '{{ctx.AppFullLink "/"}}',
-		appSubUrl: '{{AppSubUrl}}',
-		assetUrlPrefix: '{{AssetUrlPrefix}}',
-		runModeIsProd: {{.RunModeIsProd}},
-		customEmojis: {{CustomEmojis}},
-		pageData: {{.PageData}},
-		notificationSettings: {{NotificationSettings}}, {{/*a map provided by NewFuncMap in helper.go*/}}
-		enableTimeTracking: {{EnableTimetracking}},
-		mermaidMaxSourceCharacters: {{MermaidMaxSourceCharacters}},
-		sharedWorkerUri: '{{AssetURI "web_src/js/user-events.sharedworker.ts"}}',
-		{{/* this global i18n object should only contain general texts. for specialized texts, it should be provided inside the related modules by: (1) API response (2) HTML data-attribute (3) PageData */}}
-		i18n: {
-			error_occurred: {{ctx.Locale.Tr "error.occurred"}},
-			remove_label_str: {{ctx.Locale.Tr "remove_label_str"}},
-			modal_confirm: {{ctx.Locale.Tr "modal.confirm"}},
-			modal_cancel: {{ctx.Locale.Tr "modal.cancel"}},
-			more_items: {{ctx.Locale.Tr "more_items"}},
-			copy_success: {{ctx.Locale.Tr "copy_success"}},
-			copy_error: {{ctx.Locale.Tr "copy_error"}},
-		},
-	};
-	{{/* in case some pages don't render the pageData, we make sure it is an object to prevent null access */}}
-	window.config.pageData = window.config.pageData || {};
 </script>
+<script type="application/json" id="global-window-config">{{ctx.WindowConfig}}</script>
 {{ctx.ScriptImport "web_src/js/iife.ts"}}
diff --git a/web_src/js/bootstrap.ts b/web_src/js/bootstrap.ts
index f88f4900637..191279685db 100644
--- a/web_src/js/bootstrap.ts
+++ b/web_src/js/bootstrap.ts
@@ -1,15 +1,18 @@
-// DO NOT IMPORT window.config HERE!
-// to make sure the error handler always works, we should never import `window.config`, because
-// some user's custom template breaks it.
 import {showGlobalErrorMessage, processWindowErrorEvent} from './modules/errors.ts';
 
+// window.config is initialized here
+try {
+  window.config = JSON.parse(document.querySelector('#global-window-config')!.textContent);
+  // in case some pages don't render the pageData, we make sure it is an object to prevent null access
+  window.config.pageData ??= {};
+} catch {
+  showGlobalErrorMessage(`Gitea JavaScript code couldn't run correctly, please check your custom templates`);
+}
+
 // A module should not be imported twice, otherwise there will be bugs when a module has its internal states.
 // A real example is "generateElemId" in "utils/dom.ts", if it is imported twice in different module scopes,
 // It will generate duplicate IDs (ps: don't try to use "random" to fix, it is just a real example to show the importance of "do not import a module twice")
 if (!window._globalHandlerErrors?._inited) {
-  if (!window.config) {
-    showGlobalErrorMessage(`Gitea JavaScript code couldn't run correctly, please check your custom templates`);
-  }
   // we added an event handler for window error at the very beginning of <script> of page head the
   // handler calls `_globalHandlerErrors.push` (array method) to record all errors occur before
   // this init then in this init, we can collect all error events and show them.
diff --git a/web_src/js/iife.ts b/web_src/js/iife.ts
index 218519c59a3..6e2007138aa 100644
--- a/web_src/js/iife.ts
+++ b/web_src/js/iife.ts
@@ -1,6 +1,6 @@
 // This file is the entry point for the code which should block the page rendering, it is compiled by our "iife" vite plugin
 
-// bootstrap module must be the first one to be imported, it handles global errors
+// bootstrap module must be the first one to be imported, it handles global config and errors
 import './bootstrap.ts';
 
 // many users expect to use jQuery in their custom scripts (https://docs.gitea.com/administration/customizing-gitea#example-plantuml)
diff --git a/web_src/js/modules/errors.ts b/web_src/js/modules/errors.ts
index 7bf22db9623..5c62b4c5d9a 100644
--- a/web_src/js/modules/errors.ts
+++ b/web_src/js/modules/errors.ts
@@ -3,6 +3,12 @@ import {html} from '../utils/html.ts';
 import isNetworkError from 'is-network-error';
 import type {Intent} from '../types.ts';
 
+// The code in this module might be executed before window.config is initialized,
+// Don't access window.config directly.
+function windowConfig(): typeof window.config | undefined {
+  return window.config;
+}
+
 /** Extract a message string from an unknown caught value. */
 export function errorMessage(err: unknown): string {
   return (err as Error)?.message || String(err);
@@ -50,7 +56,7 @@ export function showGlobalErrorMessage(msg: string, msgType: Intent = 'error', d
 const extensionRe = /(chrome|moz|safari(-web)?)-extension:\/\//;
 export function isGiteaError(filename: string, stack: string): boolean {
   if (extensionRe.test(filename) || extensionRe.test(stack)) return false;
-  const assetBaseUrl = new URL(`${window.config.assetUrlPrefix}/`, window.location.origin).href;
+  const assetBaseUrl = new URL(`${windowConfig()?.assetUrlPrefix}/`, window.location.origin).href;
   if (filename && !filename.startsWith(assetBaseUrl) && !filename.startsWith(window.location.origin)) return false;
   return !stack || stack.includes(assetBaseUrl);
 }
@@ -64,7 +70,7 @@ export function processWindowErrorEvent({error, reason, message, type, filename,
   // - https://github.com/go-gitea/gitea/issues/20240
   if (!err) {
     if (message) console.error(new Error(message));
-    if (window.config.runModeIsProd) return;
+    if (windowConfig()?.runModeIsProd) return;
   }
 
   // Don't show network errors, happens on ref-issue when clicking on the