CVE-2023-43754: Mattermost

Medium severity, CVSS 4.3. EPSS: 0.5% chance of exploitation in the next 30 days.

Mattermost fails to check whether the  “Allow users to view archived channels”  setting is enabled during permalink previews display, allowing members to view permalink previews of archived channels even if the “Allow users to view archived channels” setting is disabled. 

Affected products

• Mattermost Mattermost: up to and including 7.8.12; from 8.0.0, up to and including 8.1.3; from 9.0.0, up to and including 9.0.1; version 9.1.0 only

Published 2023-11-27. Last modified 2026-06-17.