PoC exploit released for critical AD CS domain-takeover flaw (CVE-2026-54121)

Security researchers who discovered and reported CVE-2026-54121 (aka “Certighost”), a critical privilege elevation vulnerability in Active Directory Certificate Services (AD CS), have released a proof-of-concept (PoC) exploit for and technical details related to the flaw. The vulnerability AD CS is a Microsoft Windows Server role that lets an organization run its own Public Key Infrastructure (PKI). It acts as a Certificate Authority (CA), issuing and managing digital certificates used for authe