CVE-2026-8823

Mattermost versions 11.7.x <= 11.7.0, 10.11.x <= 10.11.17 fail to validate bot targets when demoting users to guests which allows a lower-privileged administrator to degrade arbitrary bot accounts via the standard demote-user API.. Mattermost Advisory ID: MMSA-2026-00669

Score

CVSS 3.1 3.8 Low

Status

Analyzed - responsibledisclosure@mattermost.com

Published

2026-06-22

Last modified

2026-06-22

Weaknesses

CWE-863

Affected products

• Mattermost (Mattermost)
• Mattermost Server (Mattermost)

References

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