GHSA-6HXM-W4HV-VGVW Mattermost doesn't require role-management authorization when setting the scheme_admin flag on group syncable link and patch endpoints

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 fail to require role-management authorization when setting the schemeadmin flag on group syncable link and patch endpoints, which allows a user with group-link permissions to escalate themselves and group...

Incorrect Authorization

Overview Affected versions of this package are vulnerable to Incorrect Authorization via the schemeadmin flag in group syncable link and patch endpoints. An attacker can gain unauthorized administrative privileges by sending crafted API requests. Remediation Upgrade...

CVE-2026-7387 Mattermost group syncable endpoints allow privilege escalation via scheme_admin

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 schemeadmin flag on group syncable link and patch endpoints, which allows a user with group-link permissions to escalate themselv...

CVE-2026-7387

Mattermost CVE-2026-7387 affects multiple release lines (11.6.x up to 11.6.1, 11.5.x up to 11.5.4, 10.11.x up to 10.11.15/16). The root cause is that group-syncable link and patch endpoints do not require role-management authorization when setting the scheme_admin flag, enabling a user with group...