CVE-2026-18795

Mattermost versions 11.10.x <= 11.10.0, 11.7.x <= 11.7.9, 11.9.x <= 11.9.1, 11.8.x <= 11.8.5 fail to enforce DM/GM check on server side which allows an authenticated user to quarantine a post belonging to DM or GM via direct API call.. Mattermost Advisory ID: MMSA-2026-00756

Score

CVSS 3.1 6.4 Medium

Status

Awaiting Analysis - responsibledisclosure@mattermost.com

Published

2026-10-16

Last modified

2026-10-16

Weaknesses

CWE-862

Affected products

• Mattermost (Mattermost)

References

• https://mattermost.com/security-updates