explaingit

aniqfakhrul/cve-2026-54121

Analysis updated 2026-07-26

186PythonAudience · ops devopsComplexity · 4/5Setup · hard

TLDR

A proof-of-concept tool demonstrating CVE-2026-54121 (Certighost), showing how an attacker can trick a Windows certificate authority into issuing a valid certificate for a domain controller to take over the domain.

Mindmap

mindmap
  root((repo))
    What it does
      Demonstrates CVE-2026-54121
      Tricks certificate authority
      Impersonates domain controller
    How it works
      Creates computer account
      Runs fake services
      Requests fraudulent certificate
      Extracts auth tickets
    Use cases
      Security auditing
      Penetration testing
      Vulnerability research
    Tech stack
      Python
      Windows domain
      Kerberos
    Requirements
      Admin privileges
      Network port access
      Domain credentials

Code map

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What do people build with it?

USE CASE 1

Security teams can use this tool to test whether their Windows domain certificate authority is vulnerable to CVE-2026-54121.

USE CASE 2

Penetration testers can demonstrate the full attack chain from low-privilege access to domain takeover during engagements.

USE CASE 3

IT administrators can verify that patching and configuration changes successfully block the Certighost attack path.

What is it built with?

PythonWindows Active DirectoryKerberosLDAPSMB

How does it compare?

aniqfakhrul/cve-2026-54121korroai/onklaud-5mocasus/auto-freecf
Stars186186186
LanguagePythonPythonPython
Setup difficultyhardmoderatemoderate
Complexity4/53/53/5
Audienceops devopsdeveloperdeveloper

Figures from each repo's GitHub metadata at analysis time.

How do you get it running?

Difficulty · hard Time to first run · 1h+

Requires a Windows Active Directory lab environment, domain credentials, and administrator privileges to run fake services on privileged network ports 445 and 389.

In plain English

This repository contains a proof-of-concept tool demonstrating a security vulnerability tracked as CVE-2026-54121, nicknamed Certighost. The tool shows how an attacker with limited privileges in a Windows domain environment can trick a certificate authority into issuing a valid certificate for a domain controller, which then allows the attacker to impersonate that controller and take over the domain. A detailed analysis of the vulnerability is linked from the README. The script works through a multi-step process. First, it creates a new computer account in the domain or reuses one the attacker specifies. It then starts two fake services on the attacker's machine, one mimicking a Windows file sharing service on port 445 and another mimicking a directory lookup service on port 389. These fake services are designed to intercept and respond to queries from the legitimate certificate authority. Next, the tool sends a certificate request on behalf of the newly created computer account. This request embeds special attributes that trick the certificate authority into contacting the attacker's fake services instead of the real domain controller. When the certificate authority connects to verify the request, the fake services authenticate using the attacker's computer account but respond with the identity information of the real domain controller, including its name and security identifier. Because the certificate authority believes it is issuing a certificate to the domain controller, it produces a valid certificate for that powerful account. The script then takes the final step of using this certificate to request Kerberos authentication tickets and an NT hash, giving the attacker the credentials needed to fully impersonate the domain controller. The tool must be run with administrator privileges because the fake services require access to privileged network ports. The README provides a sample command showing the required inputs, including the domain name, username, password, and the IP address of the target domain controller. Successful execution saves the stolen certificate and authentication cache files to the current directory.

Copy-paste prompts

Prompt 1
I need to test my Windows Active Directory environment for the Certighost vulnerability (CVE-2026-54121). Walk me through how to safely run this proof-of-concept tool against my lab domain controller, including what inputs I need and what output files to expect.
Prompt 2
Help me understand the CVE-2026-54121 attack chain implemented in this repo. Explain how the fake SMB and LDAP services on ports 445 and 389 trick the certificate authority into issuing a certificate for the domain controller.
Prompt 3
I am a defender trying to prevent the Certighost attack. Based on this proof-of-concept, what detection signals should I monitor for on my certificate authority and domain controller?

Frequently asked questions

What is cve-2026-54121?

A proof-of-concept tool demonstrating CVE-2026-54121 (Certighost), showing how an attacker can trick a Windows certificate authority into issuing a valid certificate for a domain controller to take over the domain.

What language is cve-2026-54121 written in?

Mainly Python. The stack also includes Python, Windows Active Directory, Kerberos.

How hard is cve-2026-54121 to set up?

Setup difficulty is rated hard, with roughly 1h+ to a first successful run.

Who is cve-2026-54121 for?

Mainly ops devops.

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