Mattermost Desktop App versions <=5.13.3 fail to attach listeners restricting navigation to external sites within the Mattermost app which allows a malicious server to expose preload script functionality to untrusted servers via having a user open an external link in their Mattermost server. Mattermost Advisory ID: MMSA-2026-00596
Exploitability
AV:NAC:LPR:LUI:RScope
S:UImpact
C:LI:LA:N4.6/CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N