CVE-2026-35392: patrickhener goshs path traversal in PUT upload handler

CVE-2026-35392 · Severity: critical · CVSS 9.8 · Published 2026-04-06

goshs is a simple web server tool used for sharing files over a network. A security flaw allows an unauthenticated attacker to upload or overwrite any file on the host system by bypassing directory restrictions. This could lead to a complete system takeover, data loss, or the installation of malicious software.

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

Quick answers

Is CVE-2026-35392 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-35392 being exploited in the wild.
How severe is CVE-2026-35392?
Critical severity, with a CVSS score of 9.8, published 6 April 2026.
Which products and versions are affected?
github.com/patrickhener/goshs (Go) SEMVER:introduced=0,fixed=1.1.5-0.20260401172448-237f3af891a9.
Is there a fix for CVE-2026-35392?
Yes. github.com/patrickhener/goshs (Go): upgrade to 1.1.5-0.20260401172448-237f3af891a9 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-35392 attacked?
It is attacked over the network, in a software library.
Am I affected by CVE-2026-35392?
Check whether you run github.com/patrickhener/goshs (Go) 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 (Go): upgrade to 1.1.5-0.20260401172448-237f3af891a9 or later
    go get github.com/patrickhener/goshs@v1.1.5-0.20260401172448-237f3af891a9

Technical details

A path traversal vulnerability exists in the PUT upload handler of goshs within `httpserver/updown.go`. The application fails to sanitize the `req.URL.Path` input, using raw string concatenation to determine the file save location without performing `filepath.Clean` or validating that the path remains within the intended webroot. An unauthenticated remote attacker can use URL-encoded traversal sequences (e.g., `%2e%2e/`) to write or overwrite arbitrary files anywhere on the host filesystem. This can be leveraged for remote code execution by overwriting sensitive system files or configuration. The issue is resolved in version 2.0.0-beta.3.

Affected products

  • patrickhener goshs < 2.0.0-beta.3

Identifiers

  • CVE-2026-35392
  • GHSA-g8mv-vp7j-qp64
  • GO-2026-5394

Timeline

  • 2026-04-02: advisory: GitHub Security Advisory published
  • 2026-04-06: disclosed: CVE published to NVD

References

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