VULNERABILITY INTELLIGENCE

CVE-2026-12882

CVSS score4.3 MEDIUM
EPSS probability0.37%
CISA KEVNot currently listed
Published2026-09-14
Last modified2026-10-07
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L

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

Weakness classification

  • responsibledisclosure@mattermost.com: CWE-407

Primary references