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CVE PROGRAM SOURCE RECORD3.5 Low

CVE-2026-9693

Mattermost thread memberships persist after team removal, exposing private channel thread metadata on re-invite

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Status
Published
Published
Updated
Assigning organization
Mattermost

Description

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 products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

Mattermost Mattermost

Default version status: unaffected

  • 10.11.0 to ≤ 10.11.20affected
  • 11.7.0 to ≤ 11.7.5affected
  • 11.9.0unaffected
  • 10.11.21unaffected
  • 11.7.6unaffected

References