CVE-2026-7387

EUVD-2026-36503
Mattermost versions 11.6.x <= 11.6.1, 11.5.x <= 11.5.4, 10.11.x <= 10.11.15, 10.11.x <= 10.11.16 Mattermost fails to require role-management authorization when setting the scheme_admin flag on group syncable link and patch endpoints, which allows a user with group-link permissions to escalate themselves and group members to team or channel admin via crafted API requests.. Mattermost Advisory ID: MMSA-2026-00665
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
MattermostCNA
8.8 HIGH
NETWORK
LOW
LOW
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Base Score
CVSS 3.x
EPSS Score
Percentile: Unknown
Early Detection
Affected products identified ahead of NVD analysis through intelligence sources.
VendorProductVersionSource
mattermostmattermost
11.6.0 ≤
𝑥
≤ 11.6.1
CNA
mattermostmattermost
11.5.0 ≤
𝑥
≤ 11.5.4
CNA
mattermostmattermost
10.11.0 ≤
𝑥
≤ 10.11.15
CNA
mattermostmattermost
10.11.0 ≤
𝑥
≤ 10.11.16
CNA
Common Weakness Enumeration
References
https://mattermost.com/security-updates