What is GHSA-c28q-m4gf-vg4q?

GHSA-c28q-m4gf-vg4q is a security advisory published by GitHub Security Advisories with Medium severity. Mattermost versions 11.6.x \u003c= 11.6.1, 11.5.x \u003c= 11.5.4, 10.11.x \u003c= 10.11.15, 10.11.x \u003c= 10.11.16...

Which CVE IDs does GHSA-c28q-m4gf-vg4q cover?

GHSA-c28q-m4gf-vg4q covers the following CVE IDs: CVE-2026-6689. Each CVE has its own detail page on EchelonGraph Pulse with the synthesized EG score.

What is the CVSS v3 score of GHSA-c28q-m4gf-vg4q?

GHSA-c28q-m4gf-vg4q has a CVSS v3 base score of 4.3, published by GitHub Security Advisories.

GHSA-c28q-m4gf-vg4qMediumCVSS 4.3

Mattermost versions 11.6.x <= 11.6.1, 11.5.x <= 11.5.4, 10.11.x <= 10.11.15, 10.11.x <= 10.11.16...

Vendor

GitHub Security Advisories

Published

June 12, 2026

Last Modified

June 12, 2026

🔗 CVE IDs covered (1)

CVE-2026-6689 →

📋 Description

Mattermost versions 11.6.x <= 11.6.1, 11.5.x <= 11.5.4, 10.11.x <= 10.11.15, 10.11.x <= 10.11.16 Fail to enforce PermissionInviteUser when setting AllowOpenInvite or AllowedDomains during team creation (the check was only applied on update/patch), which allows an authenticated user holding PermissionCreateTeam but not PermissionInviteUser on the resulting team to configure invite-controlled team settings (make the team publicly joinable via open invite and/or constrain membership via allowed domains) that they are not permitted to set on an existing team via POST /api/v4/teams with allow_open_invite: true and/or a non-empty allowed_domains in the request body.. Mattermost Advisory ID: MMSA-2026-00655

🔗 References (3)

https://nvd.nist.gov/vuln/detail/CVE-2026-6689
https://mattermost.com/security-updates
https://github.com/advisories/GHSA-c28q-m4gf-vg4q