Executive brief
Concrete CMS is a content management system used to build and manage websites. A flaw in the dashboard's sitemap reordering feature allows authenticated users with sitemap access permissions to change the display order of any pages—including pages they don't have edit rights to—without proper authorization checks. This could disrupt website navigation and page visibility in unexpected ways.
Technical details
The vulnerability is an authorization bypass in the Concrete\Controller\Backend\Dashboard\SitemapUpdate action. The controller checks only the global access_sitemap task permission before allowing page reorder operations, but fails to validate per-page edit permissions for individual pages being reordered. Additionally, the action does not validate CSRF tokens, enabling attackers to trigger reorder requests via forged cross-site requests. An authenticated user with sitemap access can modify the cDisplayOrder field of any page, regardless of their edit permissions for that page. The vulnerability affects Concrete CMS 9 before version 9.5.3, and patches are available in 9.5.3 and later.
Affected products
- Concrete CMS Concrete CMS 9 before 9.5.3
Timeline
- 2026-09-15: disclosed
- 2026-09-15: patched: Fixed in version 9.5.3