diff --git a/internal/api/handlers/management/plugin_store.go b/internal/api/handlers/management/plugin_store.go
index cab4f27f..7d8179a7 100644
--- a/internal/api/handlers/management/plugin_store.go
+++ b/internal/api/handlers/management/plugin_store.go
@@ -9,6 +9,7 @@ import (
 
 	"github.com/gin-gonic/gin"
 	"github.com/router-for-me/CLIProxyAPI/v7/internal/config"
+	"github.com/router-for-me/CLIProxyAPI/v7/internal/htmlsanitize"
 	"github.com/router-for-me/CLIProxyAPI/v7/internal/pluginhost"
 	"github.com/router-for-me/CLIProxyAPI/v7/internal/pluginstore"
 	"github.com/router-for-me/CLIProxyAPI/v7/internal/util"
@@ -81,19 +82,19 @@ func (h *Handler) ListPluginStore(c *gin.Context) {
 		status := statuses[plugin.ID]
 		installedVersion := status.InstalledVersion
 		entries = append(entries, pluginStoreListEntry{
-			ID:               plugin.ID,
-			Name:             plugin.Name,
-			Description:      plugin.Description,
-			Author:           plugin.Author,
-			Version:          plugin.Version,
-			Repository:       plugin.Repository,
-			Logo:             plugin.Logo,
-			Homepage:         plugin.Homepage,
-			License:          plugin.License,
-			Tags:             append([]string{}, plugin.Tags...),
+			ID:               htmlsanitize.String(plugin.ID),
+			Name:             htmlsanitize.String(plugin.Name),
+			Description:      htmlsanitize.String(plugin.Description),
+			Author:           htmlsanitize.String(plugin.Author),
+			Version:          htmlsanitize.String(plugin.Version),
+			Repository:       htmlsanitize.String(plugin.Repository),
+			Logo:             htmlsanitize.String(plugin.Logo),
+			Homepage:         htmlsanitize.String(plugin.Homepage),
+			License:          htmlsanitize.String(plugin.License),
+			Tags:             htmlsanitize.Strings(plugin.Tags),
 			Installed:        status.Installed,
-			InstalledVersion: installedVersion,
-			Path:             status.Path,
+			InstalledVersion: htmlsanitize.String(installedVersion),
+			Path:             htmlsanitize.String(status.Path),
 			Configured:       status.Configured,
 			Registered:       status.Registered,
 			Enabled:          status.Enabled,
@@ -104,7 +105,7 @@ func (h *Handler) ListPluginStore(c *gin.Context) {
 
 	c.JSON(http.StatusOK, pluginStoreListResponse{
 		PluginsEnabled: pluginsEnabled,
-		PluginsDir:     pluginsDir,
+		PluginsDir:     htmlsanitize.String(pluginsDir),
 		Plugins:        entries,
 	})
 }
@@ -217,9 +218,9 @@ func (h *Handler) installPluginFromStore(c *gin.Context, goos, goarch string) {
 
 	c.JSON(http.StatusOK, pluginInstallResponse{
 		Status:          "installed",
-		ID:              result.ID,
-		Version:         result.Version,
-		Path:            result.Path,
+		ID:              htmlsanitize.String(result.ID),
+		Version:         htmlsanitize.String(result.Version),
+		Path:            htmlsanitize.String(result.Path),
 		PluginsEnabled:  pluginsEnabled,
 		RestartRequired: restartRequired,
 	})
diff --git a/internal/api/handlers/management/plugin_store_test.go b/internal/api/handlers/management/plugin_store_test.go
index f707bab1..dfa8c4f1 100644
--- a/internal/api/handlers/management/plugin_store_test.go
+++ b/internal/api/handlers/management/plugin_store_test.go
@@ -7,6 +7,7 @@ import (
 	"crypto/sha256"
 	"encoding/hex"
 	"encoding/json"
+	"html"
 	"io"
 	"net/http"
 	"net/http/httptest"
@@ -79,6 +80,72 @@ func TestListPluginStoreMergesInstalledStatus(t *testing.T) {
 	}
 }
 
+func TestListPluginStoreEscapesRegistryStrings(t *testing.T) {
+	t.Parallel()
+	gin.SetMode(gin.TestMode)
+
+	h := &Handler{
+		cfg: &config.Config{
+			Plugins: config.PluginsConfig{
+				Enabled: true,
+				Dir:     t.TempDir(),
+			},
+		},
+		configFilePath:         writeTestConfigFile(t),
+		pluginStoreRegistryURL: "https://registry.example/registry.json",
+		pluginStoreHTTPClient: fakePluginStoreHTTPClient{
+			"https://registry.example/registry.json": []byte(`{
+				"schema_version": 1,
+				"plugins": [{
+					"id": "sample-provider",
+					"name": "<script>alert(1)</script>",
+					"description": "<img src=x onerror=alert(1)>",
+					"author": "\"attacker\"",
+					"version": "0.1.0",
+					"repository": "https://github.com/author-name/cliproxy-sample-provider-plugin",
+					"logo": "<svg onload=alert(1)>",
+					"homepage": "https://example.com/?q=<x>",
+					"license": "<b>MIT</b>",
+					"tags": ["<provider>", "safe & sound"]
+				}]
+			}`),
+		},
+	}
+
+	rec := httptest.NewRecorder()
+	c, _ := gin.CreateTestContext(rec)
+	c.Request = httptest.NewRequest(http.MethodGet, "/v0/management/plugin-store", nil)
+
+	h.ListPluginStore(c)
+
+	if rec.Code != http.StatusOK {
+		t.Fatalf("status = %d, want %d; body=%s", rec.Code, http.StatusOK, rec.Body.String())
+	}
+	var body pluginStoreListResponse
+	if errDecode := json.Unmarshal(rec.Body.Bytes(), &body); errDecode != nil {
+		t.Fatalf("Unmarshal() error = %v; body=%s", errDecode, rec.Body.String())
+	}
+	if len(body.Plugins) != 1 {
+		t.Fatalf("plugins len = %d, want 1", len(body.Plugins))
+	}
+	entry := body.Plugins[0]
+	if entry.Name != html.EscapeString("<script>alert(1)</script>") ||
+		entry.Description != html.EscapeString("<img src=x onerror=alert(1)>") ||
+		entry.Author != html.EscapeString(`"attacker"`) ||
+		entry.Version != "0.1.0" ||
+		entry.Repository != "https://github.com/author-name/cliproxy-sample-provider-plugin" ||
+		entry.Logo != html.EscapeString("<svg onload=alert(1)>") ||
+		entry.Homepage != html.EscapeString("https://example.com/?q=<x>") ||
+		entry.License != html.EscapeString("<b>MIT</b>") {
+		t.Fatalf("store entry = %#v, want escaped strings", entry)
+	}
+	if len(entry.Tags) != 2 ||
+		entry.Tags[0] != html.EscapeString("<provider>") ||
+		entry.Tags[1] != html.EscapeString("safe & sound") {
+		t.Fatalf("tags = %#v, want escaped strings", entry.Tags)
+	}
+}
+
 func TestInstallPluginFromStoreWritesFileAndEnablesConfig(t *testing.T) {
 	t.Parallel()
 	gin.SetMode(gin.TestMode)
diff --git a/internal/api/handlers/management/plugins.go b/internal/api/handlers/management/plugins.go
index 3b9ebc7c..6896265d 100644
--- a/internal/api/handlers/management/plugins.go
+++ b/internal/api/handlers/management/plugins.go
@@ -10,6 +10,7 @@ import (
 
 	"github.com/gin-gonic/gin"
 	"github.com/router-for-me/CLIProxyAPI/v7/internal/config"
+	"github.com/router-for-me/CLIProxyAPI/v7/internal/htmlsanitize"
 	"github.com/router-for-me/CLIProxyAPI/v7/internal/pluginhost"
 	"github.com/router-for-me/CLIProxyAPI/v7/sdk/pluginapi"
 	"gopkg.in/yaml.v3"
@@ -85,8 +86,8 @@ func (h *Handler) ListPlugins(c *gin.Context) {
 	}
 	for _, file := range files {
 		entries[file.ID] = pluginListEntry{
-			ID:           file.ID,
-			Path:         file.Path,
+			ID:           htmlsanitize.String(file.ID),
+			Path:         htmlsanitize.String(file.Path),
 			Enabled:      true,
 			ConfigFields: []pluginConfigFieldInfo{},
 			Menus:        []pluginMenuInfo{},
@@ -94,7 +95,7 @@ func (h *Handler) ListPlugins(c *gin.Context) {
 	}
 	for id, item := range configs {
 		entry := entries[id]
-		entry.ID = id
+		entry.ID = htmlsanitize.String(id)
 		entry.Configured = true
 		entry.Enabled = pluginInstanceEnabled(item)
 		if entry.ConfigFields == nil {
@@ -108,10 +109,10 @@ func (h *Handler) ListPlugins(c *gin.Context) {
 	if host != nil {
 		for _, info := range host.RegisteredPlugins() {
 			entry := entries[info.ID]
-			entry.ID = info.ID
+			entry.ID = htmlsanitize.String(info.ID)
 			entry.Registered = true
 			entry.SupportsOAuth = info.SupportsOAuth
-			entry.Logo = info.Metadata.Logo
+			entry.Logo = htmlsanitize.String(info.Metadata.Logo)
 			entry.ConfigFields = pluginConfigFields(info.Metadata.ConfigFields)
 			entry.Menus = pluginMenus(info.Menus)
 			entry.Metadata = pluginMetadata(info.Metadata)
@@ -143,7 +144,7 @@ func (h *Handler) ListPlugins(c *gin.Context) {
 
 	c.JSON(http.StatusOK, pluginListResponse{
 		PluginsEnabled: pluginsEnabled,
-		PluginsDir:     pluginsDir,
+		PluginsDir:     htmlsanitize.String(pluginsDir),
 		Plugins:        out,
 	})
 }
@@ -265,12 +266,11 @@ func pluginInstanceEnabled(item config.PluginInstanceConfig) bool {
 func pluginConfigFields(fields []pluginapi.ConfigField) []pluginConfigFieldInfo {
 	out := make([]pluginConfigFieldInfo, 0, len(fields))
 	for _, field := range fields {
-		enumValues := append([]string{}, field.EnumValues...)
 		out = append(out, pluginConfigFieldInfo{
-			Name:        field.Name,
-			Type:        string(field.Type),
-			EnumValues:  enumValues,
-			Description: field.Description,
+			Name:        htmlsanitize.String(field.Name),
+			Type:        htmlsanitize.String(string(field.Type)),
+			EnumValues:  htmlsanitize.Strings(field.EnumValues),
+			Description: htmlsanitize.String(field.Description),
 		})
 	}
 	return out
@@ -280,9 +280,9 @@ func pluginMenus(menus []pluginhost.RegisteredPluginMenu) []pluginMenuInfo {
 	out := make([]pluginMenuInfo, 0, len(menus))
 	for _, menu := range menus {
 		out = append(out, pluginMenuInfo{
-			Path:        menu.Path,
-			Menu:        menu.Menu,
-			Description: menu.Description,
+			Path:        htmlsanitize.String(menu.Path),
+			Menu:        htmlsanitize.String(menu.Menu),
+			Description: htmlsanitize.String(menu.Description),
 		})
 	}
 	return out
@@ -290,11 +290,11 @@ func pluginMenus(menus []pluginhost.RegisteredPluginMenu) []pluginMenuInfo {
 
 func pluginMetadata(meta pluginapi.Metadata) *pluginMetadataInfo {
 	return &pluginMetadataInfo{
-		Name:             meta.Name,
-		Version:          meta.Version,
-		Author:           meta.Author,
-		GitHubRepository: meta.GitHubRepository,
-		Logo:             meta.Logo,
+		Name:             htmlsanitize.String(meta.Name),
+		Version:          htmlsanitize.String(meta.Version),
+		Author:           htmlsanitize.String(meta.Author),
+		GitHubRepository: htmlsanitize.String(meta.GitHubRepository),
+		Logo:             htmlsanitize.String(meta.Logo),
 		ConfigFields:     pluginConfigFields(meta.ConfigFields),
 	}
 }
diff --git a/internal/api/handlers/management/plugins_test.go b/internal/api/handlers/management/plugins_test.go
index cff9c063..7506cebf 100644
--- a/internal/api/handlers/management/plugins_test.go
+++ b/internal/api/handlers/management/plugins_test.go
@@ -3,6 +3,7 @@ package management
 import (
 	"bytes"
 	"encoding/json"
+	"html"
 	"net/http"
 	"net/http/httptest"
 	"os"
@@ -13,6 +14,8 @@ import (
 
 	"github.com/gin-gonic/gin"
 	"github.com/router-for-me/CLIProxyAPI/v7/internal/config"
+	"github.com/router-for-me/CLIProxyAPI/v7/internal/pluginhost"
+	"github.com/router-for-me/CLIProxyAPI/v7/sdk/pluginapi"
 	"gopkg.in/yaml.v3"
 )
 
@@ -211,6 +214,58 @@ func TestPatchPluginConfigMergesAndDeletesFields(t *testing.T) {
 	}
 }
 
+func TestPluginDisplayFieldsEscapeHTML(t *testing.T) {
+	t.Parallel()
+
+	fields := pluginConfigFields([]pluginapi.ConfigField{{
+		Name:        `<img src=x onerror=alert(1)>`,
+		Type:        pluginapi.ConfigFieldTypeEnum,
+		EnumValues:  []string{`<fast>`, `safe & sound`},
+		Description: `"quoted" 'single' <b>mode</b>`,
+	}})
+	if len(fields) != 1 {
+		t.Fatalf("fields len = %d, want 1", len(fields))
+	}
+	if fields[0].Name != html.EscapeString(`<img src=x onerror=alert(1)>`) {
+		t.Fatalf("field name = %q, want escaped", fields[0].Name)
+	}
+	if fields[0].EnumValues[0] != html.EscapeString(`<fast>`) || fields[0].EnumValues[1] != html.EscapeString(`safe & sound`) {
+		t.Fatalf("enum values = %#v, want escaped values", fields[0].EnumValues)
+	}
+	if fields[0].Description != html.EscapeString(`"quoted" 'single' <b>mode</b>`) {
+		t.Fatalf("description = %q, want escaped", fields[0].Description)
+	}
+
+	menus := pluginMenus([]pluginhost.RegisteredPluginMenu{{
+		Path:        `/v0/resource/plugins/sample/<status>`,
+		Menu:        `<b>Status</b>`,
+		Description: `Shows <script>alert(1)</script>.`,
+	}})
+	if len(menus) != 1 {
+		t.Fatalf("menus len = %d, want 1", len(menus))
+	}
+	if menus[0].Path != html.EscapeString(`/v0/resource/plugins/sample/<status>`) ||
+		menus[0].Menu != html.EscapeString(`<b>Status</b>`) ||
+		menus[0].Description != html.EscapeString(`Shows <script>alert(1)</script>.`) {
+		t.Fatalf("menu = %#v, want escaped strings", menus[0])
+	}
+
+	meta := pluginMetadata(pluginapi.Metadata{
+		Name:             `<script>alert(1)</script>`,
+		Version:          `1.0.0&evil=true`,
+		Author:           `"attacker"`,
+		GitHubRepository: `https://example.com/repo?x=<script>`,
+		Logo:             `<svg onload=alert(1)>`,
+	})
+	if meta.Name != html.EscapeString(`<script>alert(1)</script>`) ||
+		meta.Version != html.EscapeString(`1.0.0&evil=true`) ||
+		meta.Author != html.EscapeString(`"attacker"`) ||
+		meta.GitHubRepository != html.EscapeString(`https://example.com/repo?x=<script>`) ||
+		meta.Logo != html.EscapeString(`<svg onload=alert(1)>`) {
+		t.Fatalf("metadata = %#v, want escaped strings", meta)
+	}
+}
+
 func writeManagementPluginFile(t *testing.T, id string) string {
 	t.Helper()
 	root := t.TempDir()
diff --git a/internal/htmlsanitize/htmlsanitize.go b/internal/htmlsanitize/htmlsanitize.go
new file mode 100644
index 00000000..ba2e4a73
--- /dev/null
+++ b/internal/htmlsanitize/htmlsanitize.go
@@ -0,0 +1,100 @@
+package htmlsanitize
+
+import (
+	"bytes"
+	"encoding/json"
+	"html"
+	"io"
+	"mime"
+	"strings"
+)
+
+// String escapes text before it is returned to browser-facing management clients.
+func String(value string) string {
+	return html.EscapeString(value)
+}
+
+// Strings escapes each string in values while preserving order.
+func Strings(values []string) []string {
+	out := make([]string, 0, len(values))
+	for _, value := range values {
+		out = append(out, String(value))
+	}
+	return out
+}
+
+// JSONBody escapes all string values in a JSON document.
+func JSONBody(body []byte) ([]byte, bool) {
+	trimmed := bytes.TrimSpace(body)
+	if len(trimmed) == 0 {
+		return body, false
+	}
+
+	decoder := json.NewDecoder(bytes.NewReader(trimmed))
+	decoder.UseNumber()
+	var value any
+	if errDecode := decoder.Decode(&value); errDecode != nil {
+		return body, false
+	}
+	var extra any
+	if errExtra := decoder.Decode(&extra); errExtra != io.EOF {
+		return body, false
+	}
+
+	var buffer bytes.Buffer
+	encoder := json.NewEncoder(&buffer)
+	encoder.SetEscapeHTML(false)
+	if errEncode := encoder.Encode(JSONValue(value)); errEncode != nil {
+		return body, false
+	}
+	return bytes.TrimSuffix(buffer.Bytes(), []byte("\n")), true
+}
+
+// JSONBodyIfLikely escapes JSON bodies when the content type or body shape indicates JSON.
+func JSONBodyIfLikely(body []byte, contentType string) ([]byte, bool) {
+	if IsJSONContentType(contentType) || LooksLikeJSON(body) {
+		return JSONBody(body)
+	}
+	return body, false
+}
+
+// JSONValue recursively escapes string values in JSON-compatible data.
+func JSONValue(value any) any {
+	switch typed := value.(type) {
+	case string:
+		return String(typed)
+	case []any:
+		out := make([]any, len(typed))
+		for index, item := range typed {
+			out[index] = JSONValue(item)
+		}
+		return out
+	case map[string]any:
+		out := make(map[string]any, len(typed))
+		for key, item := range typed {
+			out[key] = JSONValue(item)
+		}
+		return out
+	default:
+		return value
+	}
+}
+
+// IsJSONContentType reports whether contentType is application/json or a +json type.
+func IsJSONContentType(contentType string) bool {
+	mediaType, _, errParse := mime.ParseMediaType(strings.TrimSpace(contentType))
+	if errParse != nil {
+		mediaType = strings.TrimSpace(contentType)
+	}
+	mediaType = strings.ToLower(mediaType)
+	return mediaType == "application/json" || strings.HasSuffix(mediaType, "+json")
+}
+
+// LooksLikeJSON reports whether body starts with an object or array JSON marker.
+func LooksLikeJSON(body []byte) bool {
+	trimmed := bytes.TrimSpace(body)
+	if len(trimmed) == 0 {
+		return false
+	}
+	return trimmed[0] == '{' || trimmed[0] == '['
+}
diff --git a/internal/htmlsanitize/htmlsanitize_test.go b/internal/htmlsanitize/htmlsanitize_test.go
new file mode 100644
index 00000000..d88d1c65
--- /dev/null
+++ b/internal/htmlsanitize/htmlsanitize_test.go
@@ -0,0 +1,55 @@
+package htmlsanitize
+
+import (
+	"bytes"
+	"encoding/json"
+	"html"
+	"testing"
+)
+
+func TestJSONBodyEscapesStringValues(t *testing.T) {
+	t.Parallel()
+
+	got, ok := JSONBody([]byte(`{"title":"<script>alert(1)</script>","items":["safe & sound",{"description":"<b>mode</b>"}],"count":1}`))
+	if !ok {
+		t.Fatal("JSONBody() ok = false, want true")
+	}
+
+	var body map[string]any
+	if errUnmarshal := json.Unmarshal(got, &body); errUnmarshal != nil {
+		t.Fatalf("Unmarshal() error = %v; body=%s", errUnmarshal, string(got))
+	}
+	if body["title"] != html.EscapeString("<script>alert(1)</script>") {
+		t.Fatalf("title = %q, want escaped", body["title"])
+	}
+	items, okItems := body["items"].([]any)
+	if !okItems || len(items) != 2 {
+		t.Fatalf("items = %#v, want two items", body["items"])
+	}
+	if items[0] != html.EscapeString("safe & sound") {
+		t.Fatalf("items[0] = %q, want escaped", items[0])
+	}
+	nested, okNested := items[1].(map[string]any)
+	if !okNested {
+		t.Fatalf("items[1] = %#v, want object", items[1])
+	}
+	if nested["description"] != html.EscapeString("<b>mode</b>") {
+		t.Fatalf("description = %q, want escaped", nested["description"])
+	}
+	if body["count"] != float64(1) {
+		t.Fatalf("count = %#v, want unchanged number", body["count"])
+	}
+}
+
+func TestJSONBodyIfLikelySkipsNonJSONHTML(t *testing.T) {
+	t.Parallel()
+
+	body := []byte("<!doctype html><title>plugin</title>")
+	got, ok := JSONBodyIfLikely(body, "text/html; charset=utf-8")
+	if ok {
+		t.Fatal("JSONBodyIfLikely() ok = true, want false")
+	}
+	if !bytes.Equal(got, body) {
+		t.Fatalf("body = %q, want unchanged %q", string(got), string(body))
+	}
+}
diff --git a/internal/pluginhost/management.go b/internal/pluginhost/management.go
index a35b906c..a0b7f0d6 100644
--- a/internal/pluginhost/management.go
+++ b/internal/pluginhost/management.go
@@ -8,6 +8,7 @@ import (
 	"net/http"
 	"strings"
 
+	"github.com/router-for-me/CLIProxyAPI/v7/internal/htmlsanitize"
 	"github.com/router-for-me/CLIProxyAPI/v7/sdk/pluginapi"
 	log "github.com/sirupsen/logrus"
 )
@@ -255,6 +256,7 @@ func (h *Host) ServeManagementHTTP(w http.ResponseWriter, r *http.Request) bool
 		http.Error(w, "plugin management handler failed", http.StatusBadGateway)
 		return true
 	}
+	resp.Body = escapeManagementResponseBody(resp)
 
 	for keyHeader, values := range resp.Headers {
 		for _, value := range values {
@@ -330,6 +332,14 @@ func (h *Host) callManagementHandler(ctx context.Context, record managementRoute
 	return record.route.Handler.HandleManagement(ctx, req)
 }
 
+func escapeManagementResponseBody(resp pluginapi.ManagementResponse) []byte {
+	body, okEscaped := htmlsanitize.JSONBodyIfLikely(resp.Body, resp.Headers.Get("Content-Type"))
+	if !okEscaped {
+		return resp.Body
+	}
+	return body
+}
+
 func (h *Host) callResourceHandler(ctx context.Context, record resourceRouteRecord, req pluginapi.ManagementRequest) (resp pluginapi.ManagementResponse, err error) {
 	if h == nil || record.route.Handler == nil || h.isPluginFused(record.pluginID) {
 		return pluginapi.ManagementResponse{}, nil
diff --git a/internal/pluginhost/management_test.go b/internal/pluginhost/management_test.go
index 4e4507ab..319add6f 100644
--- a/internal/pluginhost/management_test.go
+++ b/internal/pluginhost/management_test.go
@@ -2,6 +2,8 @@ package pluginhost
 
 import (
 	"context"
+	"encoding/json"
+	"html"
 	"net/http"
 	"net/http/httptest"
 	"testing"
@@ -63,6 +65,63 @@ func TestRegisterManagementRoutesSkipsReservedAndUsesPriority(t *testing.T) {
 	}
 }
 
+func TestServeManagementHTMLEscapesJSONResponseStrings(t *testing.T) {
+	host := newHostWithRecords(capabilityRecord{
+		id: "json",
+		plugin: pluginapi.Plugin{Capabilities: pluginapi.Capabilities{
+			ManagementAPI: &managementPluginDouble{routes: []pluginapi.ManagementRoute{{
+				Method: http.MethodGet,
+				Path:   "/plugins/json/status",
+				Handler: managementHandlerFunc(func(context.Context, pluginapi.ManagementRequest) (pluginapi.ManagementResponse, error) {
+					return pluginapi.ManagementResponse{
+						Headers: http.Header{"Content-Type": []string{"application/json; charset=utf-8"}},
+						Body: []byte(`{
+							"title": "<script>alert(1)</script>",
+							"items": ["<b>first</b>", {"description": "safe & sound"}],
+							"count": 1
+						}`),
+					}, nil
+				}),
+			}}},
+		}},
+	})
+	host.RegisterManagementRoutes(context.Background(), nil)
+
+	req := httptest.NewRequest(http.MethodGet, "/v0/management/plugins/json/status", nil)
+	rec := httptest.NewRecorder()
+	if !host.ServeManagementHTTP(rec, req) {
+		t.Fatal("ServeManagementHTTP() = false, want true")
+	}
+	if rec.Code != http.StatusOK {
+		t.Fatalf("status = %d, want 200; body=%s", rec.Code, rec.Body.String())
+	}
+
+	var body map[string]any
+	if errDecode := json.Unmarshal(rec.Body.Bytes(), &body); errDecode != nil {
+		t.Fatalf("Unmarshal() error = %v; body=%s", errDecode, rec.Body.String())
+	}
+	if body["title"] != html.EscapeString("<script>alert(1)</script>") {
+		t.Fatalf("title = %q, want escaped", body["title"])
+	}
+	items, okItems := body["items"].([]any)
+	if !okItems || len(items) != 2 {
+		t.Fatalf("items = %#v, want two items", body["items"])
+	}
+	if items[0] != html.EscapeString("<b>first</b>") {
+		t.Fatalf("items[0] = %q, want escaped", items[0])
+	}
+	nested, okNested := items[1].(map[string]any)
+	if !okNested {
+		t.Fatalf("items[1] = %#v, want object", items[1])
+	}
+	if nested["description"] != html.EscapeString("safe & sound") {
+		t.Fatalf("nested description = %q, want escaped", nested["description"])
+	}
+	if body["count"] != float64(1) {
+		t.Fatalf("count = %#v, want unchanged number", body["count"])
+	}
+}
+
 func TestManagementHandlerPanicFusesPlugin(t *testing.T) {
 	host := newHostWithRecords(capabilityRecord{
 		id: "panic",