CVE-2026-26230 — Team Admin Privilege Escalation to Demote Members to Guest

CVE-2026-26230

Team Admin Privilege Escalation to Demote Members to Guest PUBLISHED

Description (CNA)

Mattermost versions 10.11.x <= 10.11.10 fail to properly validate permission requirements in the team member roles API endpoint which allows team administrators to demote members to guest role. Mattermost Advisory ID: MMSA-2025-00531

Affected (CNA)

Vendor / product	Versions
Mattermost / Mattermost	affected 10.11.0 through 10.11.10; unaffected 11.4.0; unaffected 10.11.11

CWE

CWE-863

References

https://mattermost.com/security-updates

ADP enrichment

CISA-ADP

No English description supplied.

No references supplied.