CVE-2026-66063 goshs has a Path Traversal issue
An unauthenticated attacker can upload files outside the served directory via path traversal in the multipart upload handler.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-66063?
CVE-2026-66063 is a medium-severity path traversal vulnerability in goshs-labs goshs, published on 28 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
goshs is a feature-rich single-binary file server for red teamers and developers. Prior to 2.1.5, the httpserver/updown.go multipart upload handler split part.FileName() on / but did not reject .., allowing an unauthenticated upload with filename .. to create a file outside the served tree. This issue is fixed in version 2.1.5.
Weakness: CWE-22
Which versions are affected by CVE-2026-66063?
11 open source packages ship an affected version, including github.com/patrickhener/goshs, github.com/patrickhener/goshs/v2 and goshs.de/goshs.
| Package | Affected | Fixed in |
|---|---|---|
github.com/patrickhener/goshs Go | All versions | None |
github.com/patrickhener/goshs Go | All versions to 1.1.4 | None |
github.com/patrickhener/goshs Go | All versions to 1.1.4 | None |
github.com/patrickhener/goshs/v2 Go | All versions | 2.1.5-0.20260727065949-f3ef599e4091 |
github.com/patrickhener/goshs/v2 Go | All versions | 2.1.5-0.20260727065949-f3ef599e4091 |
goshs.de/goshs Go | All versions | None |
5 more packages
goshs.de/goshs Go | All versions to 1.1.4 | None |
goshs.de/goshs Go | All versions to 1.1.4 | None |
goshs.de/goshs/v2 Go | All versions | 2.1.5-0.20260727065949-f3ef599e4091 |
goshs.de/goshs/v2 Go | All versions | 2.1.5-0.20260727065949-f3ef599e4091 |
goshs.de/goshs/v2 Go | All versions | 2.1.5-0.20260727065949-f3ef599e4091 |
How do I fix CVE-2026-66063?
Upgrade to a fixed version.
Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.
Is CVE-2026-66063 being exploited?
There is no known exploitation of CVE-2026-66063 in the wild and no public exploit code.
Sources
Also known as GHSA-wg2q-39h6-66x9, GO-2026-6137.