Improper access control in Contao - CVE-2026-126662
Published: November 11, 2026 / Updated: November 13, 2026
Vulnerability identifier: #VU165880
CSH Severity: Low
CVSS v4: 7.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-126662
CWE-ID: CWE-284
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to expose protected files for public download and alter synchronization settings for folders outside their assigned filemounts.
The vulnerability exists due to improper access control in Contao's DC_Folder::editAll when processing bulk folder edits without enforcing filemount containment. A remote user can use the editAll flow with table-wide protected or syncExclude field permission to publish (.public) or de-sync (.nosync) arbitrary folders outside their filemounts anywhere under the project root.
Affected software
Contao
How to mitigate CVE-2026-126662
Install security update from vendor's website.
Contao - addressed in versions 5.3.54, 5.7.17, 6.0.6