Description
Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7, 10.11.x <= 10.11.22 fail to parse Markdown autolinks with unmatched trailing closing parentheses in linear time, which allows an authenticated user with permission to create posts to cause excessive server CPU consumption and degrade availability for other users via specially crafted post or message attachment content. Mattermost Advisory ID: MMSA-2026-00703
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 ≤ 11.9.0affected11.8.0 to ≤ 11.8.4affected11.7.0 to ≤ 11.7.7affected10.11.0 to ≤ 10.11.22affected11.10.0unaffected11.9.1unaffected11.8.5unaffected11.7.8unaffected10.11.23unaffected