fix(security): headingLevel prüfen, überschreibende Tools kennzeichnen, Meta-Tools auf lit/ beschränken

- Divi-Vollformat: headingLevel nur h1 bis h6 (ValueCleaner, StoredNodeGuard, ShortformWriter);
  sonst ließ sich für Konten ohne unfiltered_html ein Skript-Element erzeugen.
- content-update, divi-update und wp-settings-update sind destructive, damit MCP-Clients nachfragen.
- mcp-adapter/execute-ability und get-ability-info nehmen auf dem OAuth-Server nur lit/-Abilities an.
- release-publish.sh übergibt den Gitea-Token per Konfigurationsdatei statt als curl-Argument.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

bin/release-publish.sh

@@ -33,27 +33,29 @@ step "ZIP prüfen"
 [[ "$(bsdtar -xOf "$zip" wp-lit-mcp/wp-lit-mcp.php | sed -n 's/^ \* Version: //p')" == "$version" ]] \
     || fail "Das ZIP enthält nicht Version $version"
 
-auth=(-H "Authorization: token $GITEA_TOKEN")
 json=(-H 'Content-Type: application/json')
-api_get() { curl -fsS "${auth[@]}" "$api/$1"; }
+# The token reaches curl as a config file on a pipe, never as an argument: argv is readable for every user (ps).
+# printf is a builtin, so the token is not in any command line here either.
+gcurl() { curl --config <(printf 'header = "Authorization: token %s"\n' "$GITEA_TOKEN") "$@"; }
+api_get() { gcurl -fsS "$api/$1"; }
 
 step "Entwurf v$version suchen oder anlegen"
 release="$(api_get 'releases?per_page=50' | jq -c --arg t "v$version" '[.[] | select(.tag_name == $t)][0] // empty')"
 if [[ -z "$release" ]]; then
     notes="$(awk -v header="= $version =" '$0 == header { on = 1; next } /^= / { on = 0 } on' readme.txt)"
-    target="$(curl -sS "${auth[@]}" "$api/tags/v$version" | jq -r '.commit.sha // empty')"
+    target="$(gcurl -sS "$api/tags/v$version" | jq -r '.commit.sha // empty')"
     [[ -n "$target" ]] || target="$(git rev-parse HEAD)"
     request="$(jq -n --arg tag "v$version" --arg sha "$target" --arg body "$notes" \
         '{tag_name: $tag, target_commitish: $sha, name: $tag, body: $body, draft: true}')"
-    release="$(curl -fsS "${auth[@]}" "${json[@]}" -d "$request" "$api/releases")" || fail "Release ließ sich nicht anlegen"
+    release="$(gcurl -fsS "${json[@]}" -d "$request" "$api/releases")" || fail "Release ließ sich nicht anlegen"
 fi
 [[ "$(jq -r .draft <<<"$release")" == "true" ]] || fail "v$version ist schon veröffentlicht"
 id="$(jq -r .id <<<"$release")"
 
 step "ZIP anhängen"
 old="$(jq -r --arg n "$name" '.assets[]? | select(.name == $n) | .id' <<<"$release")"
-[[ -z "$old" ]] || curl -fsS -X DELETE "${auth[@]}" "$api/releases/$id/assets/$old" >/dev/null
+[[ -z "$old" ]] || gcurl -fsS -X DELETE "$api/releases/$id/assets/$old" >/dev/null
-curl -fsS "${auth[@]}" -F "attachment=@$zip" "$api/releases/$id/assets?name=$name" >/dev/null \
+gcurl -fsS -F "attachment=@$zip" "$api/releases/$id/assets?name=$name" >/dev/null \
     || fail "Upload von $name fehlgeschlagen"
 
 # Read it back instead of trusting the upload: only a draft that really carries the ZIP goes public.
@@ -62,7 +64,7 @@ size="$(api_get "releases/$id" | jq -r --arg n "$name" '.assets[]? | select(.nam
 [[ "$size" == "$(stat -c %s "$zip")" ]] || fail "$name hängt nicht oder mit falscher Größe am Entwurf (Gitea: '$size')"
 
 step "Veröffentlichen"
-curl -fsS -X PATCH "${auth[@]}" "${json[@]}" -d '{"draft": false}' "$api/releases/$id" >/dev/null \
+gcurl -fsS -X PATCH "${json[@]}" -d '{"draft": false}' "$api/releases/$id" >/dev/null \
     || fail "Veröffentlichen fehlgeschlagen"
 
 step "Ergebnis von außen prüfen"

src/Access.php

@@ -4,6 +4,9 @@ declare(strict_types=1);
 
 namespace LIT\MCP;
 
+use LIT\MCP\Abilities\Errors;
+use LIT\MCP\Server\RequestContext;
+use WP_Error;
 use WP_User;
 
 defined('ABSPATH') || exit;
@@ -25,9 +28,13 @@ final class Access
         'execute_ability',
     ];
 
+    /** Meta tools of the adapter that name another ability in their input ("ability_name"). */
+    private const META_ABILITIES_BY_NAME = ['mcp-adapter/execute-ability', 'mcp-adapter/get-ability-info'];
+
     public function register(): void
     {
         add_filter('user_has_cap', [$this, 'grantCapability'], 10, 4);
+        add_filter('wp_register_ability_args', [$this, 'limitMetaToolsToOwnAbilities'], 10, 2);
 
         foreach (self::ADAPTER_META_TOOLS as $tool) {
             add_filter(
@@ -37,6 +44,36 @@ final class Access
         }
     }
 
+    /**
+     * Security audit 2026-11 (B3): the adapter's execute-ability and get-ability-info reach every ability with
+     * meta.mcp.public, from any plugin – past the Tools tab ("aus", "nur lesen"), which knows only lit/ tools.
+     * On the OAuth-protected server they therefore name lit/ abilities only.
+     *
+     * @param array<string, mixed> $args
+     * @return array<string, mixed>
+     */
+    public function limitMetaToolsToOwnAbilities(array $args, string $name): array
+    {
+        if (! in_array($name, self::META_ABILITIES_BY_NAME, true)) {
+            return $args;
+        }
+
+        $inner = $args['permission_callback'] ?? null;
+        $args['permission_callback'] = static function (mixed $input = null) use ($inner): bool|WP_Error {
+            $target = is_array($input) && is_string($input['ability_name'] ?? null) ? $input['ability_name'] : '';
+            if (RequestContext::isOAuthServerRequest() && ! str_starts_with($target, 'lit/')) {
+                return Errors::forbidden(
+                    'Über diesen Server sind nur LIT-MCP-Tools nutzbar.',
+                    'Nur Abilities mit dem Präfix lit/ ausführen oder abfragen.'
+                );
+            }
+
+            return is_callable($inner) ? $inner($input) : false;
+        };
+
+        return $args;
+    }
+
     /**
      * @return list<string>
      */

src/Integrations/Divi/Compose/ShortformWriter.php

@@ -229,7 +229,7 @@ final class ShortformWriter
                 }
                 throw new InvalidArgumentException('true oder false erwartet');
             case 'level':
-                if (is_string($value) && preg_match('/^h[1-6]$/D', $value) === 1) {
+                if (is_string($value) && preg_match(ValueCleaner::HEADING_LEVEL, $value) === 1) {
                     return $value;
                 }
                 throw new InvalidArgumentException('h1 bis h6 erwartet');

src/Integrations/Divi/Compose/StoredNodeGuard.php

@@ -294,6 +294,11 @@ final class StoredNodeGuard
             return 'Steuerzeichen im Wert – ' . self::BUILDER_ONLY . '.';
         }
 
+        // Security audit 2026-11 (B1): the rule of ValueCleaner; any other stored heading tag would become an element.
+        if ($key === 'headingLevel' && preg_match(ValueCleaner::HEADING_LEVEL, $value) !== 1) {
+            return 'headingLevel muss h1 bis h6 sein – ' . self::BUILDER_ONLY . '.';
+        }
+
         $kind = $this->cleaner->kindAt($module, $path, $subName, $key);
         if (VariableRef::contains($value)) {
             return $this->referenceProblem($value, $kind === ValueKind::Url);

src/Integrations/Divi/Compose/ValueCleaner.php

@@ -48,6 +48,12 @@ final class ValueCleaner
     /** Keys inside values: plain identifiers (ruling S13); list indexes are ints. StoredNodeGuard uses it too. */
     public const VALUE_KEY = '/^[A-Za-z0-9_-]+$/D';
 
+    /**
+     * The heading tag of a title (security audit 2026-11, B1): Divi builds the element name from headingLevel
+     * with tag_escape(), which lets "script" through, and the title text is printed raw – so only h1 to h6.
+     */
+    public const HEADING_LEVEL = '/^h[1-6]$/D';
+
     /** Last path segment naming a URL when neither kind nor key does (ruling S24): redirectUrl. */
     private const URL_SEGMENT = '/url$/i';
 
@@ -269,6 +275,11 @@ final class ValueCleaner
             throw new InvalidArgumentException('Wert ist kein gültiges UTF-8.');
         }
 
+        // Security audit 2026-11 (B1): a heading tag is an element name; no sanitizer makes "script" safe.
+        if ($key === 'headingLevel' && preg_match(self::HEADING_LEVEL, $value) !== 1) {
+            throw new InvalidArgumentException('headingLevel: h1 bis h6 erwartet.');
+        }
+
         // Step 4 (S32/S32a): control characters go on the RAW value, before the marker check and
         // before the sanitizer – the WordPress sanitizers keep them ("<" + VT is a literal "<"
         // for strip_tags), so any later strip could build a tag or a marker nobody checked.

src/Integrations/Divi/Pages/DiviUpdateAbility.php

@@ -106,7 +106,9 @@ final class DiviUpdateAbility extends DiviWriteAbility
 
     public function annotations(): array
     {
-        return Annotations::write(true);
+        // Security audit 2026-11 (B2): this overwrites existing data. destructiveHint=false would mean "only adds"
+        // to an MCP client, which then runs it without asking – the way a prompt injection reaches the site.
+        return Annotations::destructive(true);
     }
 
     /** Like lit/divi-insert: the Composer checks every changed value (Catalog, DesignRead, DynamicSources). */

src/Integrations/WordPress/Content/ContentUpdateAbility.php

@@ -97,7 +97,9 @@ final class ContentUpdateAbility implements Ability
 
     public function annotations(): array
     {
-        return Annotations::write(true);
+        // Security audit 2026-11 (B2): this overwrites existing data. destructiveHint=false would mean "only adds"
+        // to an MCP client, which then runs it without asking – the way a prompt injection reaches the site.
+        return Annotations::destructive(true);
     }
 
     public function isDirect(): bool

src/Integrations/WordPress/Settings/WpSettingsUpdateAbility.php

@@ -74,7 +74,9 @@ final class WpSettingsUpdateAbility implements Ability
 
     public function annotations(): array
     {
-        return Annotations::write(true);
+        // Security audit 2026-11 (B2): this overwrites existing data. destructiveHint=false would mean "only adds"
+        // to an MCP client, which then runs it without asking – the way a prompt injection reaches the site.
+        return Annotations::destructive(true);
     }
 
     public function isDirect(): bool

tests/Unit/AccessTest.php

@@ -7,6 +7,8 @@ namespace LIT\MCP\Tests\Unit;
 use Brain\Monkey\Filters;
 use Brain\Monkey\Functions;
 use LIT\MCP\Access;
+use LIT\MCP\Server\RequestContext;
+use WP_REST_Request;
 use WP_User;
 
 final class AccessTest extends TestCase
@@ -93,4 +95,73 @@ final class AccessTest extends TestCase
 
         self::assertNotFalse(has_filter('user_has_cap', [$access, 'grantCapability']));
     }
+
+    protected function tearDown(): void
+    {
+        RequestContext::reset();
+        parent::tearDown();
+    }
+
+    /** @return array<string, mixed> The args of a meta tool as the adapter registers them (permission always granted). */
+    private function metaToolArgs(): array
+    {
+        return ['permission_callback' => static fn (mixed $input = null): bool => true];
+    }
+
+    private function asOAuthServerRequest(): void
+    {
+        RequestContext::recordRoute(null, [], new WP_REST_Request('/mcp/mcp-oauth-server'));
+    }
+
+    public function testRegistersTheFilterThatLimitsTheAdapterMetaTools(): void
+    {
+        $access = new Access();
+        $access->register();
+
+        self::assertNotFalse(has_filter('wp_register_ability_args', [$access, 'limitMetaToolsToOwnAbilities']));
+    }
+
+    /** Security audit 2026-11, B3: execute-ability and get-ability-info may only name lit/ abilities. */
+    public function testMetaToolsRefuseForeignAbilitiesOnTheOAuthServer(): void
+    {
+        $this->asOAuthServerRequest();
+
+        foreach (['mcp-adapter/execute-ability', 'mcp-adapter/get-ability-info'] as $meta) {
+            $permission = (new Access())->limitMetaToolsToOwnAbilities($this->metaToolArgs(), $meta)['permission_callback'];
+
+            self::assertTrue($permission(['ability_name' => 'lit/guide']), $meta);
+            foreach (['akismet/comment-check', 'elementor/delete-page', 'litx/guide', '', 'LIT/guide'] as $foreign) {
+                $result = $permission(['ability_name' => $foreign]);
+
+                self::assertInstanceOf(\WP_Error::class, $result, $meta . ' ' . $foreign);
+                self::assertSame('lit_forbidden', $result->get_error_code());
+            }
+            self::assertInstanceOf(\WP_Error::class, $permission(null), 'no ability_name');
+            self::assertInstanceOf(\WP_Error::class, $permission(['ability_name' => ['lit/guide']]), 'not a string');
+        }
+    }
+
+    public function testMetaToolsKeepTheirOwnCheckOutsideTheOAuthServer(): void
+    {
+        $permission = (new Access())
+            ->limitMetaToolsToOwnAbilities($this->metaToolArgs(), 'mcp-adapter/execute-ability')['permission_callback'];
+
+        self::assertTrue($permission(['ability_name' => 'akismet/comment-check']));
+    }
+
+    public function testOtherAbilitiesAreLeftAlone(): void
+    {
+        $args = $this->metaToolArgs();
+
+        self::assertSame($args, (new Access())->limitMetaToolsToOwnAbilities($args, 'lit/guide'));
+        self::assertSame($args, (new Access())->limitMetaToolsToOwnAbilities($args, 'mcp-adapter/discover-abilities'));
+    }
+
+    public function testAMetaToolWithoutAPermissionCallbackFailsClosed(): void
+    {
+        $this->asOAuthServerRequest();
+        $permission = (new Access())->limitMetaToolsToOwnAbilities([], 'mcp-adapter/execute-ability')['permission_callback'];
+
+        self::assertFalse($permission(['ability_name' => 'lit/guide']));
+    }
 }

tests/Unit/Integrations/Divi/Compose/StoredNodeGuardTest.php

@@ -514,4 +514,20 @@ final class StoredNodeGuardTest extends TestCase
         self::assertSame([], self::guard(true, true, true)->problems($user));
         self::assertSame([], self::guard(true, true, true)->problems($private));
     }
+
+    /** Security audit 2026-11, B1: a copied heading keeps h1 to h6 only – "script" would become an element. */
+    public function testACopiedHeadingTagMustBeH1ToH6(): void
+    {
+        $heading = static fn (string $level): Block => self::block(self::node('divi/heading', ['title' => [
+            'decoration' => ['font' => ['font' => ['desktop' => ['value' => ['headingLevel' => $level]]]]],
+        ]]));
+
+        self::assertSame([], self::guard()->problems($heading('h2')));
+        foreach (['script', 'H2', 'h9', 'h2><script>'] as $level) {
+            $problems = self::guard()->problems($heading($level));
+
+            self::assertNotSame([], $problems, $level);
+            self::assertStringContainsString('headingLevel', implode(' | ', $problems));
+        }
+    }
 }

tests/Unit/Integrations/Divi/Compose/ValueCleanerTest.php

@@ -350,4 +350,39 @@ final class ValueCleanerTest extends TestCase
         self::assertFalse($cleaner->keepsId("p\x01"), 'control characters would be stripped');
         self::assertFalse($cleaner->keepsId(ComposeFixture::REFERENCE_ALT), 'an id is never a $variable reference');
     }
+
+    /** Security audit 2026-11, B1: Divi turns headingLevel into an element name, so only h1 to h6 may be stored. */
+    public function testOnlyHeadingTagsH1ToH6AreStoredAsHeadingLevel(): void
+    {
+        $cleaner = self::loopCleaner(false, false);
+        $write = static fn (string $level): mixed => $cleaner->clean(
+            'divi/heading',
+            'title.decoration.font.font',
+            ['desktop' => ['value' => ['headingLevel' => $level]]]
+        );
+
+        foreach (['h1', 'h2', 'h3', 'h4', 'h5', 'h6'] as $level) {
+            self::assertSame(['desktop' => ['value' => ['headingLevel' => $level]]], $write($level));
+        }
+        foreach (['script', 'H1', 'h7', 'h0', 'h1 ', 'h1><script>', 'style', ''] as $level) {
+            try {
+                $write($level);
+                self::fail('"' . $level . '" must be refused');
+            } catch (InvalidArgumentException $e) {
+                self::assertStringContainsString('h1 bis h6', $e->getMessage());
+            }
+        }
+    }
+
+    /** The same key is checked at any depth, also without the desktop/value wrapper. */
+    public function testHeadingLevelIsCheckedAtAnyDepth(): void
+    {
+        $this->expectException(InvalidArgumentException::class);
+
+        self::loopCleaner(false, false)->clean(
+            'divi/heading',
+            'title.decoration.font.font',
+            ['desktop' => ['headingLevel' => 'script']]
+        );
+    }
 }

tests/Unit/Integrations/Divi/Pages/DiviUpdateAbilityTest.php

@@ -308,4 +308,13 @@ final class DiviUpdateAbilityTest extends DiviWriteAbilityTestCase
         self::assertStringStartsWith('Keine Änderung', $result['summary']);
         self::assertSame([], $this->saved);
     }
+
+    /** Security audit 2026-11, B2: changing attributes of existing modules overwrites them. */
+    public function testOverwritesSoItIsMarkedDestructive(): void
+    {
+        $annotations = $this->update()->annotations();
+
+        self::assertTrue($annotations['destructive']);
+        self::assertFalse($annotations['readonly']);
+    }
 }

tests/Unit/Integrations/WordPress/Content/ContentUpdateAbilityTest.php

@@ -374,4 +374,13 @@ final class ContentUpdateAbilityTest extends TestCase
         unlink($file);
         $log->assertRecorded([]);
     }
+
+    /** Security audit 2026-11, B2: overwriting a post must not look like "only adds" to an MCP client. */
+    public function testOverwritesSoItIsMarkedDestructive(): void
+    {
+        $annotations = $this->ability(\Mockery::mock(PostWriter::class))->annotations();
+
+        self::assertTrue($annotations['destructive']);
+        self::assertFalse($annotations['readonly']);
+    }
 }

tests/Unit/Integrations/WordPress/Settings/WpSettingsAbilitiesTest.php

@@ -284,4 +284,13 @@ final class WpSettingsAbilitiesTest extends TestCase
             (new WpSettingsUpdateAbility(new SettingsWhitelist(), FakeChangeLog::forbidden()))->permission([])->get_error_code()
         );
     }
+
+    /** Security audit 2026-11, B2: site settings (front page, permalinks, title) are overwritten. */
+    public function testUpdatingSettingsIsMarkedDestructive(): void
+    {
+        $annotations = (new WpSettingsUpdateAbility(new SettingsWhitelist(), FakeChangeLog::forbidden()))->annotations();
+
+        self::assertTrue($annotations['destructive']);
+        self::assertFalse($annotations['readonly']);
+    }
 }