NVD / CVE Program· CNA GitHub_M

CVE-2026-40884: goshs: Empty-username SFTP password authentication bypass in goshs

Noroxi assessment

Priority: Monitor (action score 39/100)

The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
Probability of exploitation in the next 30 days: 0.47% (FIRST EPSS).
Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
According to CISA the attack is automatable: targets can be found by mass scanning.
Fixed version: patrickhener goshs 2.0.0-beta.6.

Low priority for now. Upgrade to patrickhener goshs 2.0.0-beta.6 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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.

CriticalCVSS 9.8 · v3.1—No exploit Fix available

Published: Apr 21, 2026
Updated: Oct 26, 2026
EPSS: 0.4% · 41th percentile
CWE: CWE-306

Report tools

JSON

Action score

Monitor

Low priority for now.

CVSS: 39 / 40 · 9.8 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.4%

CISA SSVC decision

Exploitation: proof of concept
Automatable: yes
Technical impact: total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD: —
CNA · GitHub_M: 9.8; NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

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Not in KEV: no record of exploitation in the wild
No public exploit code on record
A fix has been released

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

Vendor	Product	CPE
goshs	goshs	cpe:2.3:a:goshs:goshs

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

goshs goshsbefore 2.0.0
goshs goshs2.0.0

Versions reported by the vendor

Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.

patrickhener goshs
- < 2.0.0-beta.6affected

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

Ecosystem	Package	Affected range	Fix
Go	github.com/patrickhener/goshs	from 0	—
Go	github.com/patrickhener/goshs	up to and including 1.1.4	—
Go	github.com/patrickhener/goshs/v2	before 2.0.0	2.0.0

Same product

goshs: all records

Other highest-scoring records for the same primary product.

CVE-2026-35471Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') in goshs
39Monitor
CVE-2026-35393Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') in goshs POST multipart upload
39Monitor
CVE-2026-35392goshs has an Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') in goshs PUT Upload
39Monitor

Published before and after this one in the same product

← EarlierCVE-2026-40876Apr 21, 2026 · SFTP root escape via prefix-based path validation in goshs
34Monitor
← EarlierCVE-2026-40883Apr 21, 2026 · goshs: CSRF in state-changing GET routes enables authenticated file deletion and directory creation
24Monitor
Later →CVE-2026-40885Apr 21, 2026 · goshs: Public collaborator feed leaks .goshs ACL credentials and enables unauthorized access
30Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / package	Fixed version	Source
patrickhener goshs	2.0.0-beta.6 · description	Vendor (CNA)
Go:github.com/patrickhener/goshs/v2	2.0.0	Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

—

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

CVE-2026-408760 days apartSFTP root escape via prefix-based path validation in goshs
34Monitor

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

Anyone who can reach it over the internet can trigger it.
No account or password is required.
No user action is required.
No special conditions are required; it is repeatable.

If successful

Confidentiality: high · data can be read
Integrity: high · data or configuration can be modified
Availability: high · the service can be disrupted

Attack vector: Network
Attack complexity: Low
Privileges required: None
User interaction: None
Scope: Unchanged
Confidentiality impact: High
Integrity impact: High
Availability impact: High

Weakness class (CWE)

CWE-306 · Missing Authentication for Critical Function

CVSS vector

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

nvd-secondary

Root cause

A function added for development or support ships to production without authentication. It often relies on the assumption that it is “only reachable from the internal network.”

The bug in code

The whole CWE-306 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

1// Added for the support team
2app.post("/maintenance/reset", resetDevice);

Fixed

1if (config.maintenanceEnabled) {
2  app.post(
3    "/maintenance/reset",
4    requireSession, requireRole("admin"), resetDevice
5  );
6}

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

Attack patterns (CAPEC)

ATT&CK techniques

—

Change log

Fix✗ → ✓Sep 28, 2026, 10:45 PM UTC

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