CVE-2026-82920

Mattermost ABAC parent policy bypass via policy update endpoint

CVSS 3.1 5.5 MEDIUMCheck source for fixed versionsKEV status unknown

Original advisory

cve-program · CVE-2026-82920

Published

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

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Affected versions, risk and source history

Exploitation and risk

Source status

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cve-program · CVE-2026-82920

Published

Mattermost ABAC parent policy bypass via policy update endpoint

Source published: 14 Sep 2026 13:59:01 UTC
Source modified: 14 Sep 2026 19:23:01 UTC
Saved here: 23 Oct 2026 15:48:27 UTC
Source terms: CVE Program Terms of Use

Original source record · Cite this exact observation · Complete original publisher JSON

Source: cve-program · CVE Program Terms of Use. The publisher's wording is preserved. ChangeIntel groups the information and labels changes. The JSON record includes additional source fields.

CVSS 3.1 · 5.5 CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:L/I:L/A:N