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
mattermost: mattermost server
References1
- mattermost.com/security-updates Vendor Advisory
Metrics
- CVSS 3.1
-
3.5
LOW
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:N/A:N - EPSS — exploit probability
- 0% percentile: 20 · as of 11 November 2026
- CWE
- CWE-459
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