CVE-2023-47865: Mattermost

Medium severity, CVSS 4.3. EPSS: 0.4% chance of exploitation in the next 30 days.

Mattermost fails to check if hardened mode is enabled when overriding the username and/or the icon when posting a post. If settings allowed integrations to override the username and profile picture when posting, a member could also override the username and icon when making a post even if the Hardened Mode setting was enabled

Affected products

• Mattermost Mattermost: up to and including 7.8.12; from 8.0.0, up to and including 8.1.3

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