Permission Bypass in Mattermost GitLab Plugin by Mattermost
CVE-2026-3117

6.5MEDIUM

Key Information:

Vendor

Mattermost
Status
Mattermost
Vendor
CVE Published:
18 May 2026

What is CVE-2026-3117?

The Mattermost GitLab plugin contains a vulnerability due to inadequate permission checks when executing specific commands. This flaw permits normal users to uninstall instances or establish webhook connections using commands such as {{gitlab instance {option}}} or {{/gitlab webhook {option}}}. It poses a significant risk as it compromises the integrity of plugin management, impacting overall system security. For further details, please consult the Mattermost Advisory ID: MMSA-2026-00600.

Affected Version(s)

Mattermost 0 <= 11.1.5

Mattermost 0 <= 10.13.11

Mattermost 0 <= 11.3.4

References

https://mattermost.com/security-updates
vendor-advisory

CVSS V3.1

Score:
6.5
Severity:
MEDIUM
Confidentiality:
None
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
Low
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

daw10
.