CVE-2025-12689

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CVSS 3.1

6.5 medium

EPSS

<1%p20

Published

Dec 17, 2025 (Dec 17, 2025)

Modified

Jun 17, 2026

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.

Vendors: mattermost
Products: mattermost server
Weakness: CWE-1287
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

NVD CVE.org GitHub PoCs EPSS (0.3%)

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