GHSA-34g8-9fpp-46chMediumCVSS 5.3

Mattermost fails to limit the size of responses from integration action endpoints

Published
March 16, 2026
Last Modified
March 17, 2026

🔗 CVE IDs covered (1)

CVE-2026-2456 →

📋 Description

Mattermost versions 11.3.x <= 11.3.0, 11.2.x <= 11.2.2, 10.11.x <= 10.11.10 Mattermost fails to limit the size of responses from integration action endpoints, which allows an authenticated attacker to cause server memory exhaustion and denial of service via a malicious integration server that returns an arbitrarily large response when a user clicks an interactive message button. Mattermost Advisory ID: MMSA-2026-00571

🎯 Affected products5

  • go/github.com/mattermost/mattermost/server/v8:< 8.0.0-20260127165411-fe3052073dc6
  • go/github.com/mattermost/mattermost-server:< 5.3.2-0.20260127165411-fe3052073dc6
  • go/github.com/mattermost/mattermost-server:>= 10.11.0-rc1, < 10.11.11
  • go/github.com/mattermost/mattermost-server:>= 11.2.0-rc1, < 11.2.3
  • go/github.com/mattermost/mattermost-server:>= 11.3.0-rc1, < 11.3.1

🔗 References (4)