Contao is an Open Source CMS. From version 4.0.0 until 5.3.50 and 5.7.12, an unauthenticated visitor can submit a comment whose email or website metadata is rendered without sufficient attribute and URL encoding by listComments() in comments-bundle/contao/dca/tl_comments.php. When a backend user opens the Comments module, attacker-controlled script can execute in the Contao backend origin under that user's session. Unpublished comments remain visible to moderators, so moderation does not prevent exposure. This issue is fixed in versions 5.3.50 and 5.7.12.
History

Sat, 10 Oct 2026 08:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}


Fri, 09 Oct 2026 20:45:00 +0000

Type Values Removed Values Added
First Time appeared Contao
Contao contao
Vendors & Products Contao
Contao contao

Fri, 09 Oct 2026 19:45:00 +0000

Type Values Removed Values Added
Description Contao is an Open Source CMS. From version 4.0.0 until 5.3.50 and 5.7.12, an unauthenticated visitor can submit a comment whose email or website metadata is rendered without sufficient attribute and URL encoding by listComments() in comments-bundle/contao/dca/tl_comments.php. When a backend user opens the Comments module, attacker-controlled script can execute in the Contao backend origin under that user's session. Unpublished comments remain visible to moderators, so moderation does not prevent exposure. This issue is fixed in versions 5.3.50 and 5.7.12.
Title Contao: Cross-site scripting in the comments bundle
Weaknesses CWE-116
CWE-79
References
Metrics cvssV3_1

{'score': 9.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published: 2026-10-09T19:29:55.396Z

Updated: 2026-10-09T19:51:45.890Z

Reserved: 2026-10-08T22:34:49.291Z

Link: CVE-2026-107845

cve-icon Vulnrichment

Updated: 2026-10-09T19:51:40.383Z

cve-icon NVD

Status : Deferred

Published: 2026-10-09T20:17:10.457

Modified: 2026-10-16T17:17:04.113

Link: CVE-2026-107845

cve-icon Redhat

No data.