GHSA-247x-7qw8-fp98MediumCVSS 4.3

Mattermost doesn't rate limit login requests, allowing DoS

Published
March 25, 2026
Last Modified
April 6, 2026

🔗 CVE IDs covered (1)

CVE-2026-26233 →

📋 Description

Mattermost versions 11.4.x <= 11.4.0, 11.3.x <= 11.3.1, 11.2.x <= 11.2.3, 10.11.x <= 10.11.11 fail to rate limit login requests which allows unauthenticated remote attackers to cause denial of service (server crash and restart) via HTTP/2 single packet attack with 100+ parallel login requests.. Mattermost Advisory ID: MMSA-2025-00566

🎯 Affected products4

  • go/github.com/mattermost/mattermost-server:>= 11.4.0-rc1, < 11.4.1
  • go/github.com/mattermost/mattermost-server:>= 11.3.0-rc1, < 11.3.2
  • go/github.com/mattermost/mattermost-server:>= 11.2.0-rc1, < 11.2.4
  • go/github.com/mattermost/mattermost-server:>= 10.11.0-rc1, < 10.11.12

🔗 References (3)