Skip to content
CVE PROGRAM SOURCE RECORD6.5 Medium

CVE-2026-93849

Mattermost allows authenticated users to trigger excessive memory allocation via crafted msgpack binary WebSocket frames

Read JSON ↗CVE.org ↗
Status
Published
Published
Updated
Assigning organization
Mattermost

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

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

Mattermost Mattermost

Default version status: unaffected

  • 11.9.0 to ≤ 11.9.1affected
  • 11.8.0 to ≤ 11.8.5affected
  • 11.7.0 to ≤ 11.7.10affected
  • 11.10.0 to ≤ 11.10.1affected
  • 11.11.0unaffected
  • 11.9.2unaffected
  • 11.8.6unaffected
  • 11.7.11unaffected
  • 11.10.2unaffected

References