# CVE-2026-50138: goshs: WebDAV listener ignores --read-only, --upload-only, and --no-delete mode flags

> Authenticated WebDAV clients can modify or delete files despite read-only or upload-only restrictions, bypassing intended access controls.

- **Severity:** High 8.1 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 18 Aug 2026
- **Updated:** 19 Aug 2026
- **Also known as:** GHSA-3whc-qvhv-xqjp, GO-2026-5878

## What is CVE-2026-50138?

CVE-2026-50138 is a high-severity missing authorization vulnerability in patrickhener goshs, published on 18 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

goshs is a SimpleHTTPServer written in Go. Prior to version 2.1.0, 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. Version 2.1.0 patches the issue.

Weakness: CWE-284 (Improper Access Control)

## Which versions are affected by CVE-2026-50138?

4 open source packages ship an affected version, including goshs.de/goshs/v2 and goshs.de/goshs.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `goshs.de/goshs/v2` | Go | All versions | 2.1.0 |
| `goshs.de/goshs/v2` | Go | All versions | 2.1.0 |
| `goshs.de/goshs/v2` | Go | All versions | 2.1.0 |
| `goshs.de/goshs` | Go | All versions | None |

## How do I fix CVE-2026-50138?

Upgrade goshs.de/goshs/v2 to 2.1.0 or later.

## Is CVE-2026-50138 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-50138 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-50138 and fix it if it is affected.

What it is: CVE-2026-50138 is a high-severity missing authorization vulnerability in patrickhener goshs, published on 18 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-50138 exists.

Affected packages and fixed versions:
- goshs.de/goshs/v2 (Go): affected all versions; fixed in 2.1.0
- goshs.de/goshs/v2 (Go): affected all versions; fixed in 2.1.0
- goshs.de/goshs/v2 (Go): affected all versions; fixed in 2.1.0
- goshs.de/goshs (Go): affected all versions; no fix listed

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-50138/ (Markdown: https://insights.sbomify.com/CVE-2026-50138/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-50138
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-50138
- OSV: https://osv.dev/vulnerability/CVE-2026-50138

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-50138/
Summaries are generated and may contain mistakes; the official description above is the record.