CyberRota Analysis
This is a high severity vulnerability with a CVSS score of 7.5. It may be remotely exploitable.
CVE
CVE-2026-5740
Severity
HIGH
CVSS
7.5
EPSS
0.34%
Original NVD Description
Mattermost versions 11.6.x <= 11.6.0, 11.5.x <= 11.5.3, 11.4.x <= 11.4.4, 10.11.x <= 10.11.14 fail to properly validate msgpack-encoded WebSocket frames before memory allocation which allows an unauthenticated remote attacker to crash the server process and cause a full service outage for all users via a crafted binary WebSocket message sent to the public WebSocket endpoint.. Mattermost Advisory ID: MMSA-2026-00647
Related CVEs
Other vulnerabilities affecting the same vendor(s)