Vulnerability Description
goshs is a SimpleHTTPServer written in Go. Prior to 2.0.0-beta.6, goshs contains an SFTP root escape caused by prefix-based path validation. An authenticated SFTP user can read from and write to filesystem paths outside the configured SFTP root, which breaks the intended jail boundary and can expose or modify unrelated server files. The SFTP subsystem routes requests through sftpserver/sftpserver.go into DefaultHandler.GetHandler() in sftpserver/handler.go, which forwards file operations into readFile, writeFile, listFile, and cmdFile. All of those sinks rely on sanitizePath() in sftpserver/helper.go. helper.go uses a raw string-prefix comparison, not a directory-boundary check. Because of that, if the configured root is /tmp/goshsroot, then a sibling path such as /tmp/goshsroot_evil/secret.txt incorrectly passes validation since it starts with the same byte prefix. This vulnerability is fixed in 2.0.0-beta.6.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Goshs | Goshs | < 2.0.0 |
Related Weaknesses (CWE)
References
- https://github.com/patrickhener/goshs/security/advisories/GHSA-5h6h-7rc9-3824ExploitVendor Advisory
- https://github.com/patrickhener/goshs/security/advisories/GHSA-5h6h-7rc9-3824ExploitVendor Advisory
FAQ
What is CVE-2026-40876?
CVE-2026-40876 is a vulnerability with a CVSS score of 8.8 (HIGH). goshs is a SimpleHTTPServer written in Go. Prior to 2.0.0-beta.6, goshs contains an SFTP root escape caused by prefix-based path validation. An authenticated SFTP user can read from and write to files...
How severe is CVE-2026-40876?
CVE-2026-40876 has been rated HIGH with a CVSS base score of 8.8/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-40876?
Check the references section above for vendor advisories and patch information. Affected products include: Goshs Goshs.