CVE-2026-10600: Mattermost Server

Medium severity, CVSS 4.3. EPSS: 0.4% chance of exploitation in the next 30 days.

Mattermost versions 11.8.x <= 11.8.0, 11.7.x <= 11.7.3, 11.6.x <= 11.6.5, 10.11.x <= 10.11.20 fail to bound the time and resource consumption of server-side document content extraction which allows an authenticated user with file-upload permission to degrade file uploads for all users on the server via repeatedly uploading small documents that are cheap to upload but expensive to extract, saturating the shared extraction worker pool.. Mattermost Advisory ID: MMSA-2026-00694

Affected products

• Mattermost Mattermost Server: from 10.11.0, before 10.11.21 (fixed in 10.11.21); from 11.6.0, before 11.6.6 (fixed in 11.6.6); from 11.7.0, before 11.7.4 (fixed in 11.7.4); from 11.8.0, before 11.8.1 (fixed in 11.8.1)

Published 2026-07-27. Last modified 2026-08-03.