CVE-2026-15754

medium

Description

Mattermost versions 11.7.x <= 11.7.6, 11.8.x <= 11.8.3 The access control policy unassign endpoint fails to re-validate that each target channel still belongs to the requesting admin's team, which allows an authenticated team administrator to remove ABAC (attribute-based access control) policy assignments from channels outside their team via the policy unassign API after a channel has been moved to another team.. Mattermost Advisory ID: MMSA-2026-00718

References

https://mattermost.com/security-updates

Details

Source: Mitre, NVD

Published: 2026-08-17

Updated: 2026-08-17

Risk Information

CVSS v2

Base Score: 4.6

Vector: CVSS2#AV:N/AC:H/Au:M/C:N/I:C/A:N

Severity: Medium

CVSS v3

Base Score: 4.2

Vector: CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:N/I:H/A:N

Severity: Medium