GHSA-ff85-qw3h-g9vpMediumCVSS 5.4

Mattermost allows an attacker to edit arbitrary posts via a crafted MSTeams plugin OAuth redirect URL

Published
November 14, 2025
Last Modified
November 17, 2025

🔗 CVE IDs covered (1)

📋 Description

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.

🎯 Affected products4

  • go/github.com/mattermost/mattermost-server:>= 10.11.0, < 10.11.4
  • go/github.com/mattermost/mattermost-server:>= 10.5.0, < 10.5.12
  • go/github.com/mattermost/mattermost-server:>= 10.12.0, < 10.12.1
  • go/github.com/mattermost/mattermost/server/v8:< 8.0.0-20250929212932-a41db04d2746

🔗 References (8)