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CVE PROGRAM SOURCE RECORD9.3 Critical

CVE-2026-107845

Contao: Cross-site scripting in the comments bundle

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 Unpublished comments remain visible to moderators, so moderation does not prevent exposure.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.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

contao contao

  • >= 4.0.0, < 5.3.50affected
  • >= 5.4.0-RC1, < 5.7.12affected

References