GHSA-37j2-3vv8-cf24MediumCVSS 6.5

Mattermost doesn't validate the TIFF IFD offset in the image header before allocating memory

Published
May 26, 2026
Last Modified
June 29, 2026

🔗 CVE IDs covered (1)

CVE-2026-5755 →

📋 Description

Mattermost versions 11.6.x <= 11.6.0, 11.5.x <= 11.5.2, 11.5.x <= 11.5.3, 11.4.x <= 11.4.4, 10.11.x <= 10.11.14 fail to validate the TIFF IFD offset in the image header before allocating memory, which allows authenticated users with file upload or posting permissions to cause a denial of service (server OOM) via uploading a crafted TIFF file or posting a URL that serves one.. Mattermost Advisory ID: MMSA-2026-00648

🎯 Affected products4

  • 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

🔗 References (4)