Is CVE-2026-93849 being exploited?

No public exploit is currently tracked.

How severe is CVE-2026-93849?

CVE-2026-93849 has a CVSS v3 severity of MEDIUM (6.5).

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CVE-2026-93849

Description

Mattermost versions 11.9.x <= 11.9.1, 11.8.x <= 11.8.5, 11.7.x <= 11.7.10, 11.10.x <= 11.10.1 Mattermost fail to apply allocation limits to the byte-string decode paths in its WebSocket msgpack decoder, which allows an authenticated remote attacker to cause excessive server memory allocation via a crafted binary WebSocket frame declaring a Bin32 payload length of up to 4,294,967,295 bytes.. Mattermost Advisory ID: MMSA-2026-00768