Medium severity6.3NVD Advisory· Published Aug 17, 2026· Updated Aug 18, 2026
CVE-2026-10527
CVE-2026-10527
Description
Mattermost versions 11.7.x <= 11.7.6, 10.11.x <= 10.11.21, 11.8.x <= 11.8.3 fails to reconcile SchemeAdmin flags with a user's current role which allows a user demoted to System Guest to retain Board Admin privileges and perform admin-only operations via the Boards REST API or UI.. Mattermost Advisory ID: MMSA-2026-00691
AI Insight
LLM-synthesized narrative grounded in this CVE's description and references.
Affected products
2cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*+ 1 more
- cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*range: >=10.11.0,<10.11.22
- (no CPE)range: <=11.7.6, <=10.11.21, <=11.8.3
Patches
Vulnerability mechanics
References
1- mattermost.com/security-updatesnvdVendor Advisory
News mentions
1- Mattermost: Twelve Vulnerabilities Disclosed, Including High-Severity Permission FlawsVypr Intelligence · Aug 17, 2026