Mattermost versions 11.7.x <= 11.7.0, 11.6.x <= 11.6.2, 11.5.x <= 11.5.5, 10.11.x <= 10.11.17 Fail to validate channel ownership of an existing subscription before applying edits which allows an authenticated attacker to hijack subscriptions from channels they have no access to via a crafted PUT request to the subscription edit endpoint.. Mattermost Advisory ID: MMSA-2026-00650
Exploitability
AV:NAC:HPR:LUI:NScope
S:UImpact
C:HI:LA:L6.4/CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:L/A:LOther