---
title: "CVE-2026-40884: goshs has an empty-username SFTP password authentication bypass"
url: https://erroneo.us/security/cve/CVE-2026-40884/
description: "CVE-2026-40884 (github.com/patrickhener/goshs (Go)): goshs is a SimpleHTTPServer written in Go. Prior to 2.0.0-beta.6, goshs contains an SFTP authentication…"
type: vulnerability-record
section: "Security Digest"
date_published: 2026-04-21
date_modified: 2026-04-27
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2026-40884"
kev: false
cvss: 9.8
epss: 0.00645
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2026-40884: goshs has an empty-username SFTP password authentication bypass

**Signal:** Critical and remotely reachable. No known exploitation yet, but it is network-reachable without credentials. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- Not in CISA KEV , but CISA’s SSVC assessment records a public proof-of-concept, so attack code exists.
- EPSS 0.6% , percentile 50: FIRST’s model estimates a 0.6% chance of exploitation activity in the next 30 days, higher than 50% of all scored CVEs (moderate). EPSS is a probability, not a verdict.
- Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
- Only applies if your dependency tree includes github.com/patrickhener/goshs (Go) <= 1.1.4, no fixed version listed ; github.com/patrickhener/goshs/v2 (Go) < 2.0.0, fixed in 2.0.0 . Check your lockfile, including transitive dependencies.

## What it is

goshs is a SimpleHTTPServer written in Go. Prior to 2.0.0-beta.6, goshs contains an SFTP authentication bypass when the documented empty-username basic-auth syntax is used. If the server is started with -b ':pass' together with -sftp, goshs accepts that configuration but does not install any SFTP password handler. As a result, an unauthenticated network attacker can connect to the SFTP service and access files without a password. This vulnerability is fixed in 2.0.0-beta.6.

## Affected packages

- Go `github.com/patrickhener/goshs` <= 1.1.4 → fixed: none listed
- Go `github.com/patrickhener/goshs/v2` < 2.0.0 → fixed: 2.0.0

## Affected products (CVE record)

- patrickhener goshs: < 2.0.0-beta.6

## Severity

- GitHub_M CVSS 3.1: 9.8 `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`
- GitHub CVSS 3.1: 9.8 `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`

## Exploitation

- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation poc , automatable yes , technical impact total .
- FIRST EPSS (model of 2026-10-21): 0.65% probability of exploitation activity in the next 30 days; percentile 50.

## Sources

- [GitHub Advisory GHSA-c29w-qq4m-2gcv](https://github.com/advisories/GHSA-c29w-qq4m-2gcv)
- [CVE.org record CVE-2026-40884](https://www.cve.org/CVERecord?id=CVE-2026-40884)
- [NVD entry CVE-2026-40884](https://nvd.nist.gov/vuln/detail/CVE-2026-40884)
- [github.com](https://github.com/patrickhener/goshs/security/advisories/GHSA-c29w-qq4m-2gcv)

---
Source page: https://erroneo.us/security/cve/CVE-2026-40884/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt