CVE-2026-95666

CVE-2026-95666 affects Mattermost versions 11.9.x ≤ 11.9.1 , 11.8.x ≤ 11.8.5 , 11.7.x ≤ 11.7.10 , and 11.10.x ≤ 11.10.1 . The bulk reactions endpoint (POST /api/v4/posts/ids/reactions) fails to limit the length of the post ID array it accepts, allowing an authenticated user to cause excessive dat...