Mattermost Gitlab Plugin Permissions Bypass CVE-2026-3117 (10.13.11-11.5)
CVE-2026-3117 Published on May 18, 2026

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

Vendor Advisory NVD

Vulnerability Analysis

CVE-2026-3117 can be exploited with network access, and requires small amount of user privileges. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity, and a high impact on availability.

Attack Vector:
NETWORK
Attack Complexity:
LOW
Privileges Required:
LOW
User Interaction:
NONE
Scope:
UNCHANGED
Confidentiality Impact:
NONE
Integrity Impact:
NONE
Availability Impact:
HIGH

Weakness Type

What is an AuthZ Vulnerability?

The software does not perform an authorization check when an actor attempts to access a resource or perform an action.

CVE-2026-3117 has been classified to as an AuthZ vulnerability or weakness.


Products Associated with CVE-2026-3117

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MatterMost
 

Affected Versions

Mattermost: