CVE-2026-52771

## Summary `ApiController::deletePage()` interpolates a page tag retrieved from the database into a `DELETE FROM …_links WHERE to_tag = '$tag'` query without escaping. The page tag is attacker-controlled — the `POST /api/pages/{tag}` API accepts arbitrary URL-encoded values, including single quotes, and stores them. A low-privilege authenticated user can therefore create a page whose tag is a SQL fragment, make the page non-orphaned via the standard `{{include page="…"}}` link mechanism, and then invoke the delete endpoint to execute arbitrary SQL inside the wiki database - including time-based blind data exfiltration from any table. This is a **classic second-order SQL injection**: the `INSERT` correctly escapes the value, so the malicious tag is stored intact and the input passes every "is this value safe to put in the database?" check; the sink is the *read-back-and-reuse* path, where escaping is omitted. ## Details ### Affected component * **File:** `includes/controllers/ApiController.php` * **Method:** `ApiController::deletePage($tag)` * **Route:** `@Route("/api/pages/{tag}", methods={"DELETE"}, options={"acl":{"+"}})` — `acl:"+"` means *any authenticated user*. * **Sink:** line 626 ```php // includes/controllers/ApiController.php (v4.6.5 = origin/doryphore-dev HEAD, // lines 607–631) public function deletePage($tag) { $pageManager = $this->getService(PageManager::class); $pageController = $this->getService(PageController::class); $dbService = $this->getService(DbService::class); ... try { $page = $pageManager->getOne($tag, null, false); // (a) safe SELECT if (empty($page)) { ... } else { $tag = isset($page['tag']) ? $page['tag'] : $tag;// ^ raw tag from DB $result['notDeleted'] = [$tag]; if ($this->wiki->UserIsOwner($tag) || $this->wiki->UserIsAdmin()) { if (!$pageManager->isOrphaned($tag)) { $dbService->query( "D