CVE-2026-10527

EUVD-2026-60192
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
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
MattermostCNA
6.3 MEDIUM
NETWORK
LOW
LOW
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L
Base Score
CVSS 3.x
EPSS Score
Percentile: Unknown
Early Detection
Affected products identified ahead of NVD analysis through intelligence sources.
VendorProductVersionSource
mattermostmattermost
11.7.0 ≤
𝑥
≤ 11.7.6
CNA
mattermostmattermost
10.11.0 ≤
𝑥
≤ 10.11.21
CNA
mattermostmattermost
11.8.0 ≤
𝑥
≤ 11.8.3
CNA
Common Weakness Enumeration
References
https://mattermost.com/security-updates