CVE-2026-10085

Name of the Vulnerable Software and Affected Versions Mattermost versions 11.7.0 through 11.7.2 Mattermost versions 11.6.0 through 11.6.4 Mattermost versions 10.11.0 through 10.11.19

Description An issue exists where the system fails to restrict the group constrained channel flag to public and private channels that support group synchronization. This allows a standard member of a group or direct message to remove all other participants from the conversation by interacting with the channel patch API endpoint.

Recommendations Update Mattermost versions 11.7.0 through 11.7.2 to a version newer than 11.7.2. Update Mattermost versions 11.6.0 through 11.6.4 to a version newer than 11.6.4. Update Mattermost versions 10.11.0 through 10.11.19 to a version newer than 10.11.19.