CVE-2026-50138: patrickhener goshs access control bypass in WebDAV listener

CVE-2026-50138 · Severity: high · CVSS 8.1 · Published 2026-08-18

goshs is a tool used to serve files over the web. A security flaw allows users to bypass security restrictions like "read-only" or "no-delete" when using the WebDAV feature. This means an authorized user could delete or modify files even if the administrator explicitly configured the server to prevent such actions.

Technologies: goshs.de/goshs (Go), goshs.de/goshs/v2 (Go). Vendors: Go.

Quick answers

Is CVE-2026-50138 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-50138 being exploited in the wild.
How severe is CVE-2026-50138?
High severity, with a CVSS score of 8.1, published 18 August 2026.
Which products and versions are affected?
goshs.de/goshs (Go) SEMVER:introduced=0; goshs.de/goshs/v2 (Go) <= 2.0.9, SEMVER:introduced=0,fixed=2.1.0.
Is there a fix for CVE-2026-50138?
Yes. goshs.de/goshs/v2 (Go): upgrade to 2.1.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-50138 attacked?
It is attacked over the network, in a software library.
Am I affected by CVE-2026-50138?
Check whether you run goshs.de/goshs (Go) or goshs.de/goshs/v2 (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

  • goshs.de/goshs/v2 (Go): upgrade to 2.1.0 or later
    go get goshs.de/goshs/v2@v2.1.0

Technical details

The vulnerability is an improper access control issue (CWE-284) within the WebDAV implementation of goshs. While the primary HTTP handler correctly enforces mode-restriction flags, the WebDAV mux (located in httpserver/server.go) fails to apply the ReadOnly, UploadOnly, or NoDelete checks before passing requests to the underlying WebDAV handler. An attacker with valid credentials can use WebDAV methods like PUT, DELETE, MKCOL, MOVE, and COPY to bypass intended file system restrictions. This issue is resolved in version 2.1.0.

Affected products

  • patrickhener goshs <= 2.0.9

Identifiers

  • CVE-2026-50138
  • GHSA-3whc-qvhv-xqjp
  • GO-2026-5878

Timeline

  • 2026-05-27: other: Vulnerability reproduced by researcher
  • 2026-05-28: disclosed: Advisory published by maintainer
  • 2026-07-01: advisory: Published to GitHub Advisory Database

References

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