Vulnerability Details CVE-2026-82920
Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7 fail to enforce authorization boundaries on the access control policy update endpoint which allows a channel or team administrator to detach a system-assigned ABAC parent policy via a crafted PUT /api/v4/access_control_policies request with an empty imports list.. Mattermost Advisory ID: MMSA-2026-00724
Exploit prediction scoring system (EPSS) score
EPSS Score 0.003
EPSS Ranking 15.6%
CVSS Severity
CVSS v3 Score 5.5
References