CVE-2026-40876

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 4.0

8.7CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

CVSS 3.1

8.8CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS

0.4% chance of exploitation in the next 30 days; higher than 37% of CVEs (scores of 2026-10-26)

CWE

CWE-22

Published

2026-04-21

Modified

2026-10-26

Record from

the NVD, synced 2026-10-26

Affected

• goshs:goshs

Packages (OSV)

References

• https://github.com/patrickhener/goshs/security/advisories/GHSA-5h6h-7rc9-3824
• https://github.com/patrickhener/goshs/security/advisories/GHSA-5h6h-7rc9-3824

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