goshs has ACL Bypass & Path Traversal

Exploitation

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

CVSS

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

EPSS

• CVE-2026-66064: 0.45% estimated exploitation activity in the next 30 days; percentile 38.73 (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.

Summary sendFile derives the served filename from the raw request path while opening the file from the cleaned path, so appending a trailing slash empties the derived name and defeats both the never-serve rule for the ACL file and the block list. Finding (Medium): trailing-slash ACL and hidden-file bypass httpserver/handler.go, sendFile (lines 789-801) takes the filename from the RAW req.URL.Path while the file itself is opened from the filepath.Clean-ed path. The two disagree, and a trailing slash makes the derived name the empty string. Both protections key on that derived name, so both are defeated: the rule that never serves the .goshs ACL file, and the acl.Block list. Measured, with negative controls: Unauthenticated when the ACL is configured block-only (common usage). Stated precisely: AUTHENTICATION IS NOT BYPASSED. An unauthenticated request against a directory protected by authentication still returns 401 under the same trick; I tested that. The claim is specifically that…

Published by the source

28 Jul 2026, 22:26 UTC

Last modified by the source

18 Aug 2026, 15:00 UTC

Source last checked

26 Oct 2026, 15:27 UTC

1. Revision 3 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-964w-f6gj-5236

2. Revision 2 · amended · 24 Oct 2026

   Amended from osv record GO-2026-6134

3. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-964w-f6gj-5236

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# Patch Next advisory brief: CVE-2026-66064

Advisory: goshs has ACL Bypass & Path Traversal
IDs: CVE-2026-66064, GHSA-964w-f6gj-5236
Record: https://patchnext.com/advisories/cve-2026-66064 (revision 3, source checked 26 Oct 2026, 15:27 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 5.3)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Partial vendor fix; fixed versions by package: goshs.de/goshs/v2 2.1.5-0.20260727065949-f3ef599e4091; github.com/patrickhener/goshs/v2 2.1.5-0.20260727065949-f3ef599e4091. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go goshs.de/goshs: affected <= 1.1.4
- Go goshs.de/goshs/v2: affected <= 2.1.4; fixed in 2.1.5-0.20260727065949-f3ef599e4091
- Go github.com/patrickhener/goshs/v2: affected <= 2.1.4; fixed in 2.1.5-0.20260727065949-f3ef599e4091
- Go github.com/patrickhener/goshs: affected <= 1.1.4

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

## Supported action
No complete vendor fix is recorded. Follow the primary source's mitigation guidance and check this record again before closing anything.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on goshs.de/goshs, goshs.de/goshs/v2, github.com/patrickhener/goshs/v2, github.com/patrickhener/goshs.
- 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://osv.dev/vulnerability/GHSA-964w-f6gj-5236 (OSV record GHSA-964w-f6gj-5236 lists affected ranges: Go github.com/patrickhener/goshs/v2 >=0 =0 =0 =0 <=1.1.4)
- Verified: https://osv.dev/vulnerability/GO-2026-6134 (OSV record GO-2026-6134 lists affected ranges: Go github.com/patrickhener/goshs >=0; Go goshs.de/goshs >=0; Go goshs.de/goshs/v2 >=0 <2.1.5-0.20260727065949-f3ef599e4091 (fixed))
- Verified: https://github.com/advisories/GHSA-964w-f6gj-5236 (GitHub-reviewed advisory GHSA-964w-f6gj-5236 lists affected ranges: Go github.com/patrickhener/goshs/v2 >=0 =0 =0 =0 <=1.1.4)

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