CVEvulnerability

CVE-2026-6850

6.5 MEDIUM Published 2026-07-13 Modified 2026-07-13 Official page ↗
Status
Analyzed
Published
2026-07-13
Last modified
2026-07-13
Assigner
[email protected]
CVSS 3.1 ([email protected])
6.5 MEDIUM — CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Weaknesses
CWE-1333

Description

Mattermost versions 11.7.x <= 11.7.2, 11.6.x <= 11.6.4, 10.11.x <= 10.11.19 fail to validate the length and content of message attachment field values, which allows an authenticated attacker to cause a denial of service for all users in a channel via a post containing a specially crafted payload that triggers catastrophic backtracking in the client-side markdown parser.. Mattermost Advisory ID: MMSA-2026-00658

Affected configurations

• mattermost mattermost server (>= 10.11.0 < 10.11.20) • mattermost mattermost server (>= 11.6.0 < 11.6.5) • mattermost mattermost server (>= 11.7.0 < 11.7.3)

Related

Weakness · CWE (1)

  • CWE-1333 Inefficient Regular Expression Complexity weakness

References