CVE-2026-3117: Instance and webhook GitLab plugin commands were able to be run by non-admin users
Mattermost Plugins versions <=11.5 11.1.5 10.13.11 11.3.4.0 fail to properly check for permissions when processing commands in the Gitlab plugin which allows normal users to uninstall instances or setup webhook connections via the {{gitlab instance {option}}} or the {{/gitlab webhook {option}}} commands. Mattermost Advisory ID: MMSA-2026-00600
Affected Software
Remediation
Information
Event History
Frequently Asked Questions
What is the severity of CVE-2026-3117?
CVE-2026-3117 is considered a critical vulnerability due to its potential to allow non-admin users to execute commands that can uninstall instances or set up webhooks.
How do I fix CVE-2026-3117?
To fix CVE-2026-3117, upgrade the Mattermost GitLab plugin to a version above 11.5 or use a patched release.
What versions are affected by CVE-2026-3117?
CVE-2026-3117 affects Mattermost GitLab plugin versions 11.5 and earlier, including 11.1.5, 10.13.11, and 11.3.4.0.
Who is vulnerable to CVE-2026-3117?
Any Mattermost instances using the vulnerable GitLab plugin versions can be exploited by non-admin users.
What actions can be taken to mitigate CVE-2026-3117?
To mitigate CVE-2026-3117, restrict command usage permissions for normal users until the plugin is updated.