GitHub Advisoryadvisory · Go
GHSA-37j2-3vv8-cf24 Mattermost doesn't validate the TIFF IFD offset in the image header before allocating memory
MEDIUM
Official page ↗
- Aliases
- CVE-2026-5755
- Ecosystem
- Go
- Packages
- github.com/mattermost/mattermost-server
- Severity
- Moderate
- CVSS vector
- CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- Weaknesses
- CWE-400
- Reviewed
- 2026-06-29
Affected packages
• Go github.com/mattermost/mattermost-server: >= 11.6.0, < 11.6.1 → fixed in 11.6.1
• Go github.com/mattermost/mattermost-server: >= 11.5.0, < 11.5.4 → fixed in 11.5.4
• Go github.com/mattermost/mattermost-server: >= 11.4.0, < 11.4.5 → fixed in 11.4.5
• Go github.com/mattermost/mattermost-server: >= 10.11.0, < 10.11.15 → fixed in 10.11.15
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
Related
Alias · CVE (1)
- CVE-2026-5755 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… vulnerability
Weakness · CWE (1)
- CWE-400 Uncontrolled Resource Consumption weakness