GHSA-jp3f-x449-4q75LowCVSS 3.1

Mattermost doesn't enforce client identity binding during the OAuth authorization code redemption flow

Published
May 18, 2026
Last Modified
June 1, 2026

🔗 CVE IDs covered (1)

CVE-2026-6334 →

📋 Description

Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13 fail to enforce client identity binding during the OAuth authorization code redemption flow which allows an authenticated OAuth client to redeem authorization codes issued to a different client via a crafted token exchange request.. Mattermost Advisory ID: MMSA-2026-00570

🎯 Affected products4

  • go/github.com/mattermost/mattermost/server/v8:>= 11.5.0, < 11.5.2
  • go/github.com/mattermost/mattermost/server/v8:>= 10.11.0, < 10.11.14
  • go/github.com/mattermost/mattermost/server/v8:< 8.0.0-20260318173148-e9ae890a013b
  • go/github.com/mattermost/mattermost-server:< 5.3.2-0.20260318173148-e9ae890a013b

🔗 References (4)