GHSA-rmvv-8v8w-rf7xMediumCVSS 4.3

Mattermost doesn't validate user-supplied input in API request handlers

Published
May 26, 2026
Last Modified
June 29, 2026

🔗 CVE IDs covered (1)

CVE-2026-4646 →

📋 Description

Mattermost versions 11.6.x <= 11.6.0, 11.5.x <= 11.5.3, 11.4.x <= 11.4.4, 10.11.x <= 10.11.14 fail to validate user-supplied input in API request handlers which allows an authenticated attacker to crash the plugin process via a crafted HTTP request to the PR details endpoint. Mattermost Advisory ID: MMSA-2026-00638

🎯 Affected products5

  • go/github.com/mattermost/mattermost-server:= 11.6.0
  • go/github.com/mattermost/mattermost-server:>= 11.5.0, < 11.5.4
  • go/github.com/mattermost/mattermost-server:>= 11.4.0, < 11.4.5
  • go/github.com/mattermost/mattermost-server:>= 10.11.0, < 10.11.15
  • go/github.com/mattermost/mattermost-plugin-github:< 1.0.1-0.20260330164815-c2840e980b3c

🔗 References (4)