CVE-2026-5740highCWE-789

Unauthenticated WebSocket binary frame causes denial of service in Mattermost Server

21Vexday Risk Score

Sem sinal de exploração. Nenhum artefato público de exploração conhecido até agora.

ssvc Trackcvss 7.5epss 0.3%

probabilidade de exploração

0.3%top 73% das CVEs

exploração observada

nãonenhuma fonte reporta

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

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Produtos afetados

Mattermost · Mattermost

Referências

https://mattermost.com/security-updates