CVE-2026-107848

Contao is an Open Source CMS. From version 4.0.0 until 5.3.50 and 5.7.12, RequestTokenListener validates REQUEST_TOKEN only for POST requests, while the declarative GET guard runs only when an act parameter is present. Backend actions dispatched through the key parameter can therefore execute without a CSRF token when an authenticated backend user loads an attacker-controlled URL. Reachable actions remain limited to modules available to that user, and the advisory demonstrates destructive or state-changing actions rather than privilege escalation. This issue is fixed in versions 5.3.50 and 5.7.12.

• github.comhttps://github.com/contao/contao/commit/34dd27ee6739f10568d3d95d8784862255c925b4
• github.comhttps://github.com/contao/contao/releases/tag/5.7.12
• github.comhttps://github.com/contao/contao/security/advisories/GHSA-9ff2-p842-45wq