CVE-2025-6465: Mattermost Fails to Sanitize File Names

August 21, 2025 (updated August 29, 2025)

Mattermost versions 10.8.x <= 10.8.3, 10.5.x <= 10.5.8, 10.10.x <= 10.10.0, 10.9.x <= 10.9.3 fail to sanitize file names which allows users with file upload permission to overwrite file attachment thumbnails via path traversal in file streaming APIs.

References

github.com/advisories/GHSA-pj6f-rc94-gw53
github.com/mattermost/mattermost
mattermost.com/security-updates
nvd.nist.gov/vuln/detail/CVE-2025-6465
pkg.go.dev/vuln/GO-2025-3906

Code Behaviors & Features

Detect and mitigate CVE-2025-6465 with GitLab Dependency Scanning

Secure your software supply chain by verifying that all open source dependencies used in your projects contain no disclosed vulnerabilities. Dependency Scanning using SBOM also detects vulnerabilities from proprietary advisories that this site does not include. Learn more about Dependency Scanning using SBOM →