goshs: WebDAV listener ignores --read-only, --upload-only, and --no-delete mode flags

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

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

EPSS

• CVE-2026-50138: 0.38% estimated exploitation activity in the next 30 days; percentile 32.09 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

WebDAV listener ignores --read-only, --upload-only, and --no-delete mode flags Ecosystem: Go Package: goshs.de/goshs/v2 (github.com/patrickhener/goshs) Affected: <= v2.0.9 (every release that ships the WebDAV handler) Summary When goshs is launched with WebDAV enabled (-w), the mode-restriction flags --read-only, --upload-only, and --no-delete are enforced only on the primary HTTP port. The WebDAV port is wired straight to golang.org/x/net/webdav.Handler with no equivalent guard, so an authenticated WebDAV client can PUT, DELETE, MKCOL, MOVE, and COPY despite the operator's stated intent. Details httpserver/server.go:207-238 — the WebDAV mux registers only IPWhitelistMiddleware, ServerHeaderMiddleware, and optionally BasicAuthMiddleware. There is no fs.ReadOnly || fs.UploadOnly || fs.NoDelete check on the WebDAV path. The HTTP mux in the same file (lines 134-204) does check these flags on every state-changing route. Proof of concept Impact - Integrity — --read-only and --no-delete…

Published by the source

1 Jul 2026, 21:56 UTC

Last modified by the source

1 Jul 2026, 21:56 UTC

Source last checked

26 Oct 2026, 15:24 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-3whc-qvhv-xqjp

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# Patch Next advisory brief: CVE-2026-50138

Advisory: goshs: WebDAV listener ignores --read-only, --upload-only, and --no-delete mode flags
IDs: CVE-2026-50138, GHSA-3whc-qvhv-xqjp
Record: https://patchnext.com/advisories/cve-2026-50138 (revision 1, source checked 26 Oct 2026, 15:24 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 8.1)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: goshs.de/goshs/v2 2.1.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go goshs.de/goshs/v2: affected <= 2.0.9; fixed in 2.1.0

## Suggested inspection (read-only)
- Go goshs.de/goshs/v2: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on goshs.de/goshs/v2.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-3whc-qvhv-xqjp (GitHub-reviewed advisory GHSA-3whc-qvhv-xqjp lists affected ranges: Go goshs.de/goshs/v2 >=0 <=2.0.9)

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