Path traversal in Contao - CVE-2026-126663
Published: November 11, 2026 / Updated: November 13, 2026
Vulnerability identifier: #VU165881
CSH Severity: Low
CVSS v4: 5.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-126663
CWE-ID: CWE-22
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to disclose the visual content of image-type files outside their granted files/ scope, including above the project root.
The vulnerability exists due to path traversal in Contao's image insert tag when validating raw paths before percent-decoding without enforcing base-directory containment in ImageFactory::create(). A remote user can supply a percent-encoded traversal path through the {{image::*}} insert tag as a content editor to make the server read, resize and serve image-type files outside the permitted directory.
Affected software
Contao
How to mitigate CVE-2026-126663
Install security update from vendor's website.
Contao - addressed in versions 5.3.54, 5.7.17, 6.0.6