CVE-2026-9859
CVE CVE-2026-9859EUVD EUVD-2026-60541Published 2026-08-17T22:06:26.000ZLast changed 2026-08-18T14:22:01.000ZCVSS 6.5
What the advisory describes
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
Source: EUVD (ENISA), in the words of the advisory.
Products the advisory names
These come from the advisory itself, not from any check we performed.
- Mattermost — Mattermost 11.7.0 ≤11.7.6; 10.11.0 ≤10.11.21; 11.8.0 ≤11.8.3
The versions shown are the advisory's own. Patchlage compares no version numbers and derives no judgement from them — which version is installed is something a person has to look up.
Carried in the product catalogue
An estate covering these products can be recorded in Patchlage. An advisory about them appears in the next morning's situation report.
- Mattermost — Mattermost
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