CVE-2026-82920
mediumMattermost 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…
Vendor / product: Mattermost — mattermost server
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
CVSS
5.5
5.5 (CVSS v3.1)
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:L/I:L/A:N Severity source: NVD CVSS v3.1 (responsibledisclosure@mattermost.com)
Timeline (UTC)
Published: 2026-09-14 14:17
Modified: 2026-10-07 18:04
NVD status: Analyzed
Last synced 1 day ago
Verified against the source API 2026-10-27 06:52 UTC
Exploitation
Not listed in CISA KEV (as of last catalog sync)
Absence from KEV does not mean a CVE is not exploited. Exploitation status: unknown (no authoritative evidence in our sources).
Affected products
mattermost / mattermost_server ≥11.7.0 <11.7.8, ≥11.8.0 <11.8.5, ≥11.9.0 <11.9.1
Weakness classification (CWE)
Source: NVD / CISA. “NVD-CWE-Other” and “NVD-CWE-noinfo” mean NVD could not assign a specific weakness.
Mitigation & advisories
Vendor advisory: https://mattermost.com/security-updates
References
- https://mattermost.com/security-updates responsibledisclosure@mattermost.com
Data sources
NVD CVE API 2.0 — fetched 2026-10-27 06:52 UTC · record ↗