CVEvulnerability

CVE-2026-5163

6.5 MEDIUM Published 2026-05-18 Modified 2026-10-14 Official page ↗
Status
Analyzed
Published
2026-05-18
Last modified
2026-10-14
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:H/I:N/A:N
Weaknesses
CWE-862

Description

Mattermost versions 11.5.x <= 11.5.1 fail to verify channel membership when processing AI-assisted message rewrites which allows an authenticated attacker to read the content of threads in private channels and direct messages they do not have access to via a crafted request to the post rewrite endpoint.. Mattermost Advisory ID: MMSA-2026-00645

Affected configurations

• mattermost mattermost server (>= 11.5.0 < 11.5.2)

Related

Weakness · CWE (1)

  • CWE-862 Missing Authorization weakness

References