CVE-2026-9816 | BDVDB-2026-360412 Detail
MattermostMattermost
Description#
Mattermost versions 11.7.x <= 11.7.6, 10.11.x <= 10.11.21, 11.8.x <= 11.8.3 fail to validate BoardMember.Scheme* fields server-side on insert and archive-import paths which allows a board editor or non-guest team member to grant board admin to arbitrary users via POST /api/v2/boards/{boardID}/members and POST /api/v2/teams/{teamID}/archive/import.. Mattermost Advisory ID: MMSA-2026-00685
Impact#
Per CVSS v3.1: confidentiality impact low, integrity impact high, availability impact high. Attack vector: network.
Weaknesses#
- CWE-863 Incorrect Authorization
References#
Exploit#
No public exploit known
History#
- Version 1Record published in the CVE List.
- Version 2Most recent update recorded in the CVE List.