Certighost (CVE-2026-54121) - AD CS Domain Controller Impersonation

Overview Certighost is an Active Directory Certificate Services vulnerability disclosed on July 24, 2026 by researchers H0j3n and aniqfakhrul. It allows a low-privileged domain user to impersonate a Domain Controller and achieve full domain compromise, including DCSync and krbtgt extraction. Patched in the July 2026 Patch Tuesday as CVE-2026-54121. If your Enterprise CA has not been updated, patch now. CVE: CVE-2026-54121 Researchers: H0j3n, aniqfakhrul Patched: July 14, 2026 Disclosed: July 24, 2026 Impact: Full domain compromise from low-privileged user Affected component: Active Directory Certificate Services - Enterprise CA Background AD CS is Microsoft’s PKI implementation. It issues X.509 certificates used for authentication. A client requests a certificate from an Enterprise CA, then presents it to the KDC via PKINIT to obtain a Kerberos TGT. ...

July 26, 2026 · 4 min · Tony Merisan

CVE-2026-26128 — Kerberos Reflection Bypass: Detection & Mitigation

1. Overview CVE-2026-26128 is a Kerberos authentication reflection bypass discovered by Synacktiv that completely bypasses the patch introduced for CVE-2025-33073. It allows an attacker to obtain SYSTEM-level access on most Windows builds. CVE CVE-2026-26128 Discovered by Synacktiv Patched March 2026 Patch Tuesday Related CVE-2025-33073, CVE-2025-58726, CVE-2026-24294 Impact Local Privilege Escalation → SYSTEM Affected All Windows versions except Windows 11 24H2 (default config) 2. Background The broader context of this vulnerability sits within a chain of authentication reflection research: ...

July 6, 2026 · 3 min · Tony Merisan