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.

CVE-2026-40876 · Severity: high · CVSS 8.8 · Published 2026-04-21

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.

Technologies: github.com/patrickhener/goshs (Go), github.com/patrickhener/goshs/v2 (Go), Goshs. Vendors: Go, Goshs.

Quick answers

Is CVE-2026-40876 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-40876 being exploited in the wild.
How severe is CVE-2026-40876?
High severity, with a CVSS score of 8.8, published 21 April 2026.
Which products and versions are affected?
github.com/patrickhener/goshs (Go) <= 1.1.4, SEMVER:introduced=0, SEMVER:introduced=0,last_affected=1.1.4; github.com/patrickhener/goshs/v2 (Go) < 2.0.0, SEMVER:introduced=0,fixed=2.0.0.
Is there a fix for CVE-2026-40876?
Yes. github.com/patrickhener/goshs/v2 (Go): upgrade to 2.0.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
Am I affected by CVE-2026-40876?
Check whether you run github.com/patrickhener/goshs (Go), github.com/patrickhener/goshs/v2 (Go) or Goshs at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

  • github.com/patrickhener/goshs/v2 (Go): upgrade to 2.0.0 or later
    go get github.com/patrickhener/goshs/v2@v2.0.0

Affected products

  • github.com/patrickhener/goshs (Go) <= 1.1.4, SEMVER:introduced=0, SEMVER:introduced=0,last_affected=1.1.4
  • github.com/patrickhener/goshs/v2 (Go) < 2.0.0, SEMVER:introduced=0,fixed=2.0.0
  • Goshs

Identifiers

  • CVE-2026-40876
  • GHSA-5h6h-7rc9-3824
  • GO-2026-5146

References

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