fix: restrict content-query by cap before pagination, filter hidden fields

Review fix round 1: content-query now excludes posts/statuses the user
cannot edit before querying (author restriction without edit_others_posts,
status filtering by edit_private_posts/edit_published_posts) instead of
only dropping them after fetching, and rejects unknown field/taxonomy
filters. content-types' not-found hint only lists editable types.
PostPresenter skips Pods password fields and readonly protected meta.
Query input gains search/terms length limits.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01At3V6SjwbMe6eMzVGW3Hs7

src/Integrations/WordPress/Content/ContentQueryAbility.php

@@ -6,6 +6,7 @@ namespace LIT\MCP\Integrations\WordPress\Content;
 
 use LIT\MCP\Abilities\Ability;
 use LIT\MCP\Abilities\Cursor;
+use LIT\MCP\Abilities\Errors;
 use LIT\MCP\Integrations\WordPress\PostGuard;
 use LIT\MCP\Integrations\WordPress\Schema\ContentSchema;
 use WP_Error;
@@ -48,12 +49,17 @@ final class ContentQueryAbility implements Ability
                     'items' => ['type' => 'string', 'enum' => self::STATUSES],
                     'description' => 'Standard: alle außer Papierkorb.',
                 ],
-                'search' => ['type' => 'string'],
+                'search' => ['type' => 'string', 'maxLength' => 200],
                 'taxonomy' => [
                     'type' => 'object',
                     'properties' => [
                         'taxonomy' => ['type' => 'string'],
-                        'terms' => ['type' => 'array', 'minItems' => 1, 'items' => ['type' => ['integer', 'string']]],
+                        'terms' => [
+                            'type' => 'array',
+                            'minItems' => 1,
+                            'maxItems' => 50,
+                            'items' => ['type' => ['integer', 'string']],
+                        ],
                     ],
                     'required' => ['taxonomy', 'terms'],
                     'additionalProperties' => false,
@@ -115,6 +121,22 @@ final class ContentQueryAbility implements Ability
             return Cursor::invalid();
         }
 
+        $postType = (string) $input['post_type'];
+
+        if (isset($input['field']) && is_array($input['field'])) {
+            $error = $this->rejectUnlessKnownField($postType, (string) $input['field']['key']);
+            if ($error !== null) {
+                return $error;
+            }
+        }
+
+        if (isset($input['taxonomy']) && is_array($input['taxonomy'])) {
+            $error = $this->rejectUnlessKnownTaxonomy($postType, (string) $input['taxonomy']['taxonomy']);
+            if ($error !== null) {
+                return $error;
+            }
+        }
+
         $limit = Cursor::limit($input['limit'] ?? null);
         $posts = get_posts(array_merge($this->queryArgs($input), [
             'posts_per_page' => $limit + 1,
@@ -138,9 +160,13 @@ final class ContentQueryAbility implements Ability
      */
     private function queryArgs(array $input): array
     {
+        $postType = (string) $input['post_type'];
+        $typeObject = get_post_type_object($postType);
+        $caps = is_object($typeObject) && isset($typeObject->cap) ? $typeObject->cap : null;
+
         $args = [
-            'post_type' => (string) $input['post_type'],
-            'post_status' => $input['status'] ?? self::STATUSES,
+            'post_type' => $postType,
+            'post_status' => $this->allowedStatuses((array) ($input['status'] ?? self::STATUSES), $caps),
             'orderby' => (string) ($input['orderby'] ?? 'date'),
             'order' => strtoupper((string) ($input['order'] ?? 'desc')),
             'no_found_rows' => true,
@@ -148,6 +174,13 @@ final class ContentQueryAbility implements Ability
             'suppress_filters' => false,
         ];
 
+        // Without edit_others_posts, even a status the user may edit in principle must
+        // stay limited to their own posts – otherwise the query would leak drafts etc.
+        // of other authors that happen to pass the per-status gate below.
+        if (! current_user_can($this->capability($caps, 'edit_others_posts'))) {
+            $args['author'] = get_current_user_id();
+        }
+
         if (isset($input['search']) && $input['search'] !== '') {
             $args['s'] = (string) $input['search'];
         }
@@ -204,4 +237,63 @@ final class ContentQueryAbility implements Ability
 
         return count($clauses) > 1 ? array_merge(['relation' => 'OR'], $clauses) : $clauses;
     }
+
+    /**
+     * Drops statuses the current user has no right to edit at all, so the query never
+     * even fetches rows that would only be discarded by the per-post check afterwards
+     * (which would otherwise waste a page slot and reveal the post existed).
+     *
+     * @param list<mixed> $statuses
+     * @return list<string>
+     */
+    private function allowedStatuses(array $statuses, ?object $caps): array
+    {
+        $gates = [
+            'private' => $this->capability($caps, 'edit_private_posts'),
+            'publish' => $this->capability($caps, 'edit_published_posts'),
+            'future' => $this->capability($caps, 'edit_published_posts'),
+        ];
+
+        return array_values(array_filter(
+            array_map('strval', $statuses),
+            static fn (string $status): bool => ! isset($gates[$status]) || current_user_can($gates[$status])
+        ));
+    }
+
+    private function capability(?object $caps, string $name): string
+    {
+        return $caps !== null && isset($caps->{$name}) ? (string) $caps->{$name} : $name;
+    }
+
+    private function rejectUnlessKnownField(string $postType, string $key): ?WP_Error
+    {
+        $allowed = array_keys($this->schema->fields($postType));
+        if (in_array($key, $allowed, true)) {
+            return null;
+        }
+
+        return Errors::invalidInput(
+            sprintf('Feld "%s" ist für Inhaltstyp "%s" nicht verfügbar.', $key, $postType),
+            ['field.key' => 'unbekanntes Feld'],
+            $allowed === []
+                ? 'Für diesen Inhaltstyp sind keine Felder verfügbar.'
+                : 'Verfügbare Felder: ' . implode(', ', $allowed) . '.'
+        );
+    }
+
+    private function rejectUnlessKnownTaxonomy(string $postType, string $taxonomy): ?WP_Error
+    {
+        $allowed = array_column($this->schema->taxonomies($postType), 'name');
+        if (in_array($taxonomy, $allowed, true)) {
+            return null;
+        }
+
+        return Errors::invalidInput(
+            sprintf('Taxonomie "%s" ist für Inhaltstyp "%s" nicht verfügbar.', $taxonomy, $postType),
+            ['taxonomy.taxonomy' => 'unbekannte Taxonomie'],
+            $allowed === []
+                ? 'Für diesen Inhaltstyp sind keine Taxonomien verfügbar.'
+                : 'Verfügbare Taxonomien: ' . implode(', ', $allowed) . '.'
+        );
+    }
 }

src/Integrations/WordPress/Content/ContentTypesAbility.php

@@ -99,13 +99,22 @@ final class ContentTypesAbility implements Ability
         if ($description === null) {
             return Errors::notFound(
                 sprintf('Inhaltstyp "%s" ist nicht verfügbar.', $postType),
-                'Verfügbare Inhaltstypen: ' . implode(', ', $this->schema->postTypeNames()) . '.'
+                'Verfügbare Inhaltstypen: ' . implode(', ', $this->editableTypeNames()) . '.'
             );
         }
 
         return ['post_types' => [$description]];
     }
 
+    /** @return list<string> */
+    private function editableTypeNames(): array
+    {
+        return array_values(array_filter(
+            $this->schema->postTypeNames(),
+            fn (string $name): bool => $this->canEdit($name)
+        ));
+    }
+
     /**
      * Only post types the user can edit are listed or described (spec §4.5): requesting
      * a managed but non-editable type is a forbidden error, not a silent omission.

src/Integrations/WordPress/Content/PostPresenter.php

@@ -7,6 +7,7 @@ namespace LIT\MCP\Integrations\WordPress\Content;
 use LIT\MCP\Abilities\JsonMap;
 use LIT\MCP\Abilities\Rev;
 use LIT\MCP\Integrations\WordPress\Schema\ContentSchema;
+use LIT\MCP\Integrations\WordPress\Schema\FieldDefinition;
 use WP_Post;
 
 /**
@@ -143,12 +144,31 @@ class PostPresenter
     {
         $result = [];
         foreach ($this->schema->fields((string) $post->post_type) as $key => $field) {
+            if ($this->isHidden($field)) {
+                continue;
+            }
+
             $result[$key] = $this->schema->sourceOf($field)->read((int) $post->ID, $field);
         }
 
         return $result;
     }
 
+    /**
+     * Pods password fields and readonly protected meta (WordPress' own "_"-prefixed
+     * internal keys) are never read out via lit-content-get/-query: neither belongs in
+     * front of the model, and both are one plugin registration away from leaking secrets
+     * or internal engine state.
+     */
+    private function isHidden(FieldDefinition $field): bool
+    {
+        if ($field->type === 'password') {
+            return true;
+        }
+
+        return $field->status !== FieldDefinition::WRITABLE && str_starts_with($field->key, '_');
+    }
+
     /** @return array{id: int, url: string, alt: string}|null */
     private function featuredImage(WP_Post $post): ?array
     {