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French agency warns of Mattermost Server flaw that bypasses security policy
France's national cyber agency CERT-FR published an advisory on 29 October 2026 about a flaw in Mattermost Server, a team chat platform. The flaw lets an attacker get around the software's security policy. Versions 11.7 before 11.7.11, 11.8 before 11.8.6, and 11.9 before 11.9.2 are affected, and the fixes are listed in Mattermost's own security bulletin of 28 October 2026.
What does it mean?
If you run Mattermost Server, a chat tool used by teams, an update is needed to close a hole that could let someone get past its security rules. The affected versions are 11.7 before 11.7.11, 11.8 before 11.8.6, and 11.9 before 11.9.2.
Who is affected?
Organizations and IT administrators who run Mattermost Server versions listed as affected.