low3.5
CVE-2026-107848
Contao: Cross-site request forgery in custom backend actions
Impact
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.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| composer | contao/core-bundle | >= 4.0.0, < 5.3.50 | 5.3.50 |