Medium severity6.5NVD Advisory· Published Aug 17, 2026
CVE-2026-9859
CVE-2026-9859
Description
Mattermost versions 11.7.x <= 11.7.6, 10.11.x <= 10.11.21, 11.8.x <= 11.8.3 fail to enforce PermissionManageBoardRoles on the channelId field of the batch endpoint, which allows an authenticated board editor to relink any board they can edit to an arbitrary channel via a crafted PATCH request. Mattermost Advisory ID: MMSA-2026-00686
AI Insight
LLM-synthesized narrative grounded in this CVE's description and references.
Affected products
1- Range: <=11.7.6, <=10.11.21, <=11.8.3
Patches
Vulnerability mechanics
References
1News mentions
0No linked articles in our index yet.