CVE-2026-40189: goshs is a SimpleHTTPServer written in Go

Q: How do I fix CVE-2026-40189?

goshs: upgrade to 2.0.0. Exact commands for each OS are on this page.

Q: Is CVE-2026-40189 being exploited?

CVE-2026-40189 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-40189 affect?

CVE-2026-40189 affects goshs. Severity is critical (CVSS 9.8). goshs is a SimpleHTTPServer written in Go. Prior to 2.0.0-beta.4, goshs enforces the documented per-folder .goshs ACL/basic-auth mechanism for directory listings and file reads, but it does not enforce the same authorization checks for stat

Q: How urgent is CVE-2026-40189?

Priority 60/100. Critical severity; Public exploit reference; CISA SSVC: automatable with total technical impact; Remotely exploitable, no login, no user action

This week

CRITICAL 9.8REMOTEUPGRADE

CVE-2026-40189 is a critical-severity flaw (CVSS 9.8) affecting goshs. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

goshs is a SimpleHTTPServer written in Go. Prior to 2.0.0-beta.4, goshs enforces the documented per-folder .goshs ACL/basic-auth mechanism for directory listings and file reads, but it does not enforce the same authorization checks for state-changing routes. An unauthenticated attacker can upload files with PUT, upload files with multipart POST /upload, create directories with ?mkdir, and delete files with ?delete inside a .goshs-protected direct

Why this priority

Critical severity
Public exploit reference
CISA SSVC: automatable with total technical impact
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.6% (top 49%)
CISA exploited list	No
Weakness	CWE-862
Published	2026-04-10
Last modified	2026-10-26

Publisher (CNA): GitHub, Inc. · Vendor: goshs

Last updated 2026-10-26 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-04-10 20:16 UTCPublished CVE record published
2026-10-26 22:10 UTCUpdated Record last modified

goshs goshs UPGRADE

Affected: < 2.0.0 · 2.0.0 beta1 · 2.0.0 beta2 · 2.0.0 beta3

Fixed in: 2.0.0

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy goshs || rpm -q goshs || goshs --version

2. UPGRADE to 2.0.0 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade goshs

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade goshs

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Exact fixes by distribution

Go · github.com/patrickhener/goshs · NO FIX YET · vulnerable: <= 1.1.4 · source

Fedora ELN · openbao · FIXED · 2.6.5-1.eln159 · FEDORA-2026-77adf886ae · source

sudo dnf upgrade --advisory=FEDORA-2026-77adf886ae

Fedora 46 · sugar-turtleart · FIXED · 220-16.fc46 · FEDORA-2026-b79483c788 · source

sudo dnf upgrade --advisory=FEDORA-2026-b79483c788

Public exploits and detection

Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.

Write-up: github.com/patrickhener/goshs/security/advisories/GHSA-wvhv-qcqf-f3cx

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-40189?

goshs: upgrade to 2.0.0. Exact commands for each OS are on this page.

Is CVE-2026-40189 being exploited?

CVE-2026-40189 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-40189 affect?

CVE-2026-40189 affects goshs. Severity is critical (CVSS 9.8). goshs is a SimpleHTTPServer written in Go. Prior to 2.0.0-beta.4, goshs enforces the documented per-folder .goshs ACL/basic-auth mechanism for directory listings and file reads, but it does not enforce the same authorization checks for stat

How urgent is CVE-2026-40189?

Priority 60/100. Critical severity; Public exploit reference; CISA SSVC: automatable with total technical impact; Remotely exploitable, no login, no user action

Related CVEs

CVE-2026-40876 HIGH 8.8 UPGRADE goshs is a SimpleHTTPServer written in Go
CVE-2026-40884 CRITICAL 9.8 UPGRADE goshs is a SimpleHTTPServer written in Go
CVE-2026-40885 HIGH 8.8 DOWNGRADE goshs is a SimpleHTTPServer written in Go
CVE-2026-40903 CRITICAL 9.1 UPGRADE goshs is a SimpleHTTPServer written in Go
CVE-2026-40188 HIGH 7.7 UPGRADE goshs is a SimpleHTTPServer written in Go

References

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