CVE-2026-9693

Summary

Mattermost versions 10.11.x <= 10.11.20, 11.7.x <= 11.7.5 Mattermost fails to remove thread membership records when a user is removed from or leaves a team, which allows a previously removed user who is later re-invited to the team to view private channel thread root post content and metadata via the team threads API.. Mattermost Advisory ID: MMSA-2026-00682

Affected Software

VendorProductVersion RangeStatus
MattermostMattermost10.11.0 <= 10.11.20affected
MattermostMattermost11.7.0 <= 11.7.5affected
MattermostMattermost11.9.0unaffected
MattermostMattermost10.11.21unaffected
MattermostMattermost11.7.6unaffected

Weaknesses

  • CWE-459: CWE-459: Incomplete Cleanup

References