CVE-2026-5163
6.5
Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
Exploitability: 2.8 / Impact: 3.6
Source: responsibledisclosure@mattermost.com (Secondary)
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 (1)
Products: Mattermost: Mattermost Server
Configuration A
| Vulnerable Software | Affected Versions |
|---|---|
| From 11.5.0 to 11.5.2 |
References (1)
Timeline
No history available yet.