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

Description (CNA)

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

Affected (CNA)

Vendor / product	Versions
Mattermost / Mattermost	affected 11.6.0 through 11.6.1; affected 11.5.0 through 11.5.4; affected 10.11.0 through 10.11.15; affected 10.11.0 through 10.11.16; unaffected 11.7.0; unaffected 11.6.2; unaffected 11.5.5; unaffected 10.11.16; unaffected 10.11.17

CWE

CWE-863

References

https://mattermost.com/security-updates

ADP enrichment

CISA-ADP

No English description supplied.

No references supplied.