CVE-2026-9859 — Mattermost Boards plugin didn’t enforce role-based authorization on board channel link allowing board editors to expos…

CVE-2026-9859

Mattermost Boards plugin didn’t enforce role-based authorization on board channel link allowing board editors to expose boards to arbitrary channels PUBLISHED

Description (CNA)

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

Affected (CNA)

Vendor / product	Versions
Mattermost / Mattermost	affected 11.7.0 through 11.7.6; affected 10.11.0 through 10.11.21; affected 11.8.0 through 11.8.3; unaffected 11.9.0; unaffected 11.7.7; unaffected 10.11.22; unaffected 11.8.4

CWE

CWE-863

References

https://mattermost.com/security-updates

ADP enrichment

CISA-ADP

No English description supplied.

No references supplied.