All vulnerabilities
CVE-2026-107845GHSA-628f-v4f6-p37r

contao/comments-bundle: Contao: Cross-site scripting in the comments bundle

contao contao/comments-bundlecomposerLibraries & packages
Open in ThreatlineRecord JSON
CVSS
9.3Critical
ExploitationNo known exploitationNot in CISA KEV, which does not prove it is unexploitedCISA KEV
Exploit odds (EPSS)0.27%Chance of exploitation activity in the next 30 days, higher than 18% of CVEs. Scored 23 Oct 2026FIRST EPSS
Fixed in5.3.50Also 5.7.12GitHub
Published9 Oct 2026Updated 9 Oct 2026CVE List

What fixes it

  • 5.3.50contao/comments-bundle, composerGitHubcomposer require "contao/comments-bundle:^5.3.50"
  • 5.7.12contao/comments-bundle, composerGitHubcomposer require "contao/comments-bundle:^5.7.12"
  • 5.3.50contao/comments-bundle, PackagistOSVcomposer require "contao/comments-bundle:^5.3.50"
  • 5.7.12contao/comments-bundle, PackagistOSVcomposer require "contao/comments-bundle:^5.7.12"

A fixed version on one release line is not the upgrade target for every line. Check your exact version and any vendor backports.

Description

An unauthenticated front end visitor can post a comment containing a XSS injection. The victim is any back end user who opens the Comments module, and moderation makes exposure certain rather than preventing it. No Content-Security-Policy header is sent on the Contao back end, so nothing mitigates the inline handler.

Impact

Anyone on the internet can inject script that executes in the Contao back end origin, under the session of whichever user opens the Comments module, with no click and no hover. From there the payload acts as that user through the back end: reading any module they can reach, creating a new administrator, or editing a template, which on Contao is a documented path from back end write access to code execution. Moderation does not help and in fact guarantees exposure, since unpublished comments are still inserted and a moderator has to open the list to act on them.

Text from GitHub Advisory Database

Affected versions 106

  • contao/comments-bundle, composer>= 4.0.0, < 5.3.50GitHub
  • contao/comments-bundle, composer>= 5.4.0-RC1, < 5.7.12GitHub
  • contaoaffected: >= 4.0.0, < 5.3.50CVE List
  • contaoaffected: >= 5.4.0-RC1, < 5.7.12CVE List
  • contao/comments-bundle, Packagistfrom 4.0.0, fixed in 5.3.50OSV
  • contao/comments-bundle, Packagist4.0.0OSV
  • contao/comments-bundle, Packagist4.0.1OSV
  • contao/comments-bundle, Packagist4.0.2OSV
  • contao/comments-bundle, Packagist4.0.3OSV
  • contao/comments-bundle, Packagist4.1.0OSV
  • contao/comments-bundle, Packagist4.1.0-RC1OSV
  • contao/comments-bundle, Packagist4.1.0-beta1OSV
  • contao/comments-bundle, Packagist4.1.1OSV
  • contao/comments-bundle, Packagist4.1.2OSV
  • contao/comments-bundle, Packagist4.10.0OSV
  • contao/comments-bundle, Packagist4.10.0-RC1OSV
  • contao/comments-bundle, Packagist4.10.0-RC2OSV
  • contao/comments-bundle, Packagist4.10.0-RC3OSV
  • contao/comments-bundle, Packagist4.10.0-RC4OSV
  • contao/comments-bundle, Packagist4.10.1OSV
  • contao/comments-bundle, Packagist4.10.2OSV
  • contao/comments-bundle, Packagist4.10.3OSV
  • contao/comments-bundle, Packagist4.10.4OSV
  • contao/comments-bundle, Packagist4.10.5OSV
  • contao/comments-bundle, Packagist4.10.6OSV
  • contao/comments-bundle, Packagist4.10.7OSV
  • contao/comments-bundle, Packagist4.11.0OSV
  • contao/comments-bundle, Packagist4.11.0-RC1OSV
  • contao/comments-bundle, Packagist4.11.0-RC2OSV
  • contao/comments-bundle, Packagist4.11.1OSV
  • contao/comments-bundle, Packagist4.11.2OSV
  • contao/comments-bundle, Packagist4.11.3OSV
  • contao/comments-bundle, Packagist4.11.4OSV
  • contao/comments-bundle, Packagist4.11.5OSV
  • contao/comments-bundle, Packagist4.11.6OSV
  • contao/comments-bundle, Packagist4.11.7OSV
  • contao/comments-bundle, Packagist4.11.8OSV
  • contao/comments-bundle, Packagist4.11.9OSV
  • contao/comments-bundle, Packagist4.12.0OSV
  • contao/comments-bundle, Packagist4.12.0-RC1OSV
  • contao/comments-bundle, Packagist4.12.0-RC2OSV
  • contao/comments-bundle, Packagist4.12.0-RC3OSV
  • contao/comments-bundle, Packagist4.12.1OSV
  • contao/comments-bundle, Packagist4.12.2OSV
  • contao/comments-bundle, Packagist4.12.3OSV
  • contao/comments-bundle, Packagist4.12.4OSV
  • contao/comments-bundle, Packagist4.12.5OSV
  • contao/comments-bundle, Packagist4.12.6OSV
  • contao/comments-bundle, Packagist4.12.7OSV
  • contao/comments-bundle, Packagist4.13.0OSV
  • contao/comments-bundle, Packagist4.13.0-RC1OSV
  • contao/comments-bundle, Packagist4.13.0-RC2OSV
  • contao/comments-bundle, Packagist4.13.0-RC3OSV
  • contao/comments-bundle, Packagist4.13.1OSV
  • contao/comments-bundle, Packagist4.13.10OSV
  • contao/comments-bundle, Packagistfrom 5.4.0-RC1, fixed in 5.7.12OSV
  • contao/comments-bundle, Packagist5.4.0OSV
  • contao/comments-bundle, Packagist5.4.0-RC1OSV
  • contao/comments-bundle, Packagist5.4.0-RC2OSV
  • contao/comments-bundle, Packagist5.4.0-RC3OSV
  • contao/comments-bundle, Packagist5.4.0-RC4OSV
  • contao/comments-bundle, Packagist5.4.1OSV
  • contao/comments-bundle, Packagist5.4.10OSV
  • contao/comments-bundle, Packagist5.4.11OSV
  • contao/comments-bundle, Packagist5.4.12OSV
  • contao/comments-bundle, Packagist5.4.13OSV
  • contao/comments-bundle, Packagist5.4.14OSV
  • contao/comments-bundle, Packagist5.4.2OSV
  • contao/comments-bundle, Packagist5.4.3OSV
  • contao/comments-bundle, Packagist5.4.4OSV
  • contao/comments-bundle, Packagist5.4.5OSV
  • contao/comments-bundle, Packagist5.4.6OSV
  • contao/comments-bundle, Packagist5.4.7OSV
  • contao/comments-bundle, Packagist5.4.8OSV
  • contao/comments-bundle, Packagist5.4.9OSV
  • contao/comments-bundle, Packagist5.5.0OSV
  • contao/comments-bundle, Packagist5.5.0-RC1OSV
  • contao/comments-bundle, Packagist5.5.0-RC2OSV
  • contao/comments-bundle, Packagist5.5.0-RC3OSV
  • contao/comments-bundle, Packagist5.5.0-RC4OSV
  • contao/comments-bundle, Packagist5.5.1OSV
  • contao/comments-bundle, Packagist5.5.10OSV
  • contao/comments-bundle, Packagist5.5.11OSV
  • contao/comments-bundle, Packagist5.5.12OSV
  • contao/comments-bundle, Packagist5.5.13OSV
  • contao/comments-bundle, Packagist5.5.14OSV
  • contao/comments-bundle, Packagist5.5.15OSV
  • contao/comments-bundle, Packagist5.5.16OSV
  • contao/comments-bundle, Packagist5.5.2OSV
  • contao/comments-bundle, Packagist5.5.3OSV
  • contao/comments-bundle, Packagist5.5.4OSV
  • contao/comments-bundle, Packagist5.5.5OSV
  • contao/comments-bundle, Packagist5.5.6OSV
  • contao/comments-bundle, Packagist5.5.7OSV
  • contao/comments-bundle, Packagist5.5.8OSV
  • contao/comments-bundle, Packagist5.5.9OSV
  • contao/comments-bundle, Packagist5.6.0OSV
  • contao/comments-bundle, Packagist5.6.0-RC1OSV
  • contao/comments-bundle, Packagist5.6.0-RC2OSV
  • contao/comments-bundle, Packagist5.6.0-RC3OSV
  • contao/comments-bundle, Packagist5.6.1OSV
  • contao/comments-bundle, Packagist5.6.10OSV
  • contao/comments-bundle, Packagist5.6.11OSV
  • contao/comments-bundle, Packagist5.6.2OSV
  • contao/comments-bundle, Packagist5.6.3OSV
  • contao/comments-bundle, Packagist5.6.4OSV

References 5