CVE-2025-12689EPSS p19.9%

CVE-2025-12689CVE-2025-12689

mattermost / mattermost_server

Description

Mattermost versions 11.0.x <= 11.0.4, 10.12.x <= 10.12.2, 10.11.x <= 10.11.6 fail to check WebSocket request field for proper UTF-8 format, which allows attacker to crash Calls plug-in via sending malformed request.

Scoring

CVSS 6.5 ()
VectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS0.29% probability of exploitation · percentile 19.9% · 2026-10-17T12:00:28Z
Last modified2026-10-13
Sourced from NVD + FIRST.org EPSS. Curated for EU compliance use cases by Adam Lundqvist, Founder at SQUR.