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OpenAdvisories
Medium · 5.0 CVE-2026-10542 EUVD-2026-77366GHSA-462g-wr4w-p54m

Playbooks channel action update validation issue

Published Sep 14, 2026 · Updated Sep 14, 2026 · Assigned by Mattermost

Description

Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7, 10.11.x <= 10.11.22 fail to validate channel action ownership which allows channel managers to update actions in other channels via the channel action update endpoint.. Mattermost Advisory ID: MMSA-2026-00692

Affected products

VendorProductAffectedFixed
Mattermost Mattermost 11.9.0 – ≤ 11.9.0, 11.8.0 – ≤ 11.8.4, 11.7.0 – ≤ 11.7.7, 10.11.0 – ≤ 10.11.22 11.10.0

References