CVE-2026-93849 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
- Exploited in the wild
- Not known
- Fix
- None listed
What is CVE-2026-93849?
CVE-2026-93849 is a medium-severity vulnerability in Mattermost, published on 26 Oct 2026.
Official 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
Weakness: CWE-789
Which versions are affected by CVE-2026-93849?
How do I fix CVE-2026-93849?
No fix has been published for CVE-2026-93849 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-93849 being exploited?
There is no known exploitation of CVE-2026-93849 in the wild and no public exploit code.
Sources
Also known as GHSA-w44p-jxhf-26w5.