CVE-2025-55073

Mattermost versions 10.11.x <= 10.11.3, 10.5.x <= 10.5.11, 10.12.x <= 10.12.0 fail to validate the relationship between the post being updated and the MSTeams plugin OAuth flow which allows an attacker to edit arbitrary posts via a crafted MSTeams plugin OAuth redirect URL.

Score

CVSS 3.1 5.4 Medium

Status

Analyzed - responsibledisclosure@mattermost.com

Published

2025-11-14

Last modified

2026-10-19

Weaknesses

CWE-306

Affected products

• Mattermost (Mattermost)
• Mattermost Server (Mattermost)

References

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