CVE-2026-54121 — Active Directory Certificate Services Elevation of Privilege Vulnerability

Executive Summary

Improper authorization in Active Directory Certificate Services (AD CS) allows an authorized attacker to elevate privileges over a network.

Overview

8.8

CVSS HIGH

Critical

MS Severity

Not Exploited

MS Exploit Status

Less Likely

MS Exploit Likelihood

Category Elevation of Privilege

Weakness CWE-285: Improper Authorization

Released Jul 14 2026

Last Updated Jul 14 2026

Publicly Disclosed No

CISA KEV Not Listed

Known Exploits None Known

EPSS Score 0.01052 — 0.6137 percentile

NVD CVSS 8.8 HIGH — matches MSRC

CVSS Vector

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

ATTACK VECTOR

Network

ATTACK COMPLEXITY

Low

PRIVILEGES REQUIRED

Low

USER INTERACTION

None

SCOPE

Unchanged

CONFIDENTIALITY

High

INTEGRITY

High

AVAILABILITY

High

EXPLOIT CODE MATURITY

Unproven

REMEDIATION LEVEL

Official Fix

REPORT CONFIDENCE

Confirmed

Temporal Score: 7.7

EPSS Score

0.01052

probability of exploitation in the next 30 days

0.6137 percentile - updated 2026-08-14

View on FIRST.org

Affected Products

15 affected products

Product	KB Article	Severity	Impact	Restart Required
Windows 10 Version 1607 for 32-bit Systems	`5099535 (Security Update)`	Critical	Elevation of Privilege	Yes
Windows 10 Version 1607 for x64-based Systems	`5099535 (Security Update)`	Critical	Elevation of Privilege	Yes
Windows 10 Version 1809 for 32-bit Systems	`5099538 (Security Update)`	Critical	Elevation of Privilege	Yes
Windows 10 Version 1809 for x64-based Systems	`5099538 (Security Update)`	Critical	Elevation of Privilege	Yes
Windows Server 2012	`5099445 (Monthly Rollup)`	Critical	Elevation of Privilege	Yes
Windows Server 2012 (Server Core installation)	`5099445 (Monthly Rollup)`	Critical	Elevation of Privilege	Yes
Windows Server 2012 R2	`5099444 (Monthly Rollup)`	Critical	Elevation of Privilege	Yes
Windows Server 2012 R2 (Server Core installation)	`5099444 (Monthly Rollup)`	Critical	Elevation of Privilege	Yes
Windows Server 2016	`5099535 (Security Update)`	Critical	Elevation of Privilege	Yes
Windows Server 2016 (Server Core installation)	`5099535 (Security Update)`	Critical	Elevation of Privilege	Yes
Windows Server 2019	`5099538 (Security Update)`	Critical	Elevation of Privilege	Yes
Windows Server 2019 (Server Core installation)	`5099538 (Security Update)`	Critical	Elevation of Privilege	Yes
Windows Server 2022	`5099540 (Security Update)`	Critical	Elevation of Privilege	Yes
Windows Server 2025	`5099536 (Security Update)`	Critical	Elevation of Privilege	Yes
Windows Server 2025 (Server Core installation)	`5099536 (Security Update)`	Critical	Elevation of Privilege	Yes

Patches

6 patches

Article	Type	Restart
`5099535`	Security Update	Yes
`5099538`	Security Update	Yes
`5099445`	Monthly Rollup	Yes
`5099444`	Monthly Rollup	Yes
`5099540`	Security Update	Yes
`5099536`	Security Update	Yes

Exploits & PoC

12 public PoCs

Unverified third-party code

Public proof-of-concept repositories aggregated from PoC-in-GitHub. They are not reviewed and may be incomplete, non-functional, or malicious — inspect the code before running anything.

Repository	Stars	Published	Description
aniqfakhrul/CVE-2026-54121	324	2026-07-23	Certighost POC
tc4dy/CVE-2026-54121-PoC-Exploit	27	2026-07-25	👻 CVE-2026-54121 - Best CertiGhost AD CS Multi-Exploit Framework \| Advanced toolkit with rogue DC/LDAP servers, certificate abuse, PKINIT hash extraction. Features: detect safe check, exploit full mul
marcgoam/CVE-2026-54121-CertiGhost	10	2026-07-27	CVE-2026-54121 (Certighost) AD CS DC-impersonation PoC. Patched SAN handling + MAQ-safe account reuse.
nafiez/Metasploit-CVE-2026-54121-Certighost	4	2026-07-31	A Metasploit auxiliary module that escalates from any low-privileged domain user to full domain compromise by abusing the AD CS enrollment "chase" fallback. The CA can be coerced into authenticating
0xBlackash/CVE-2026-54121	2	2026-07-25	CVE-2026-54121
ChPratik/CVE-2026-54121	1	2026-07-28	Improper authorization in Active Directory Certificate Services (AD CS) allows an authorized attacker to elevate privileges over a network.
KrakenEU/CVE-2026-54121-CertiGhost	1	2026-07-31	CVE-2026-54121(CertiGhost) without MachineAccountQuota POC
HORKimhab/CVE-2026-54121	0	2026-07-25	CVE-2026-54121 - Draft
GlendonNotGlen/certighost-cve-2026-54121-slides	0	2026-07-26	Slidev presentation for Certighost (CVE-2026-54121), with Mermaid diagrams and exported assets.
AtlasVector/Certighost-CVE-2026-54121	0	2026-08-03	Splunk detection writeup for CVE-2026-54121 (CertiGhost): AD CS certificate chase abuse leading to full domain compromise. Lab-validated detection, triage steps, and incident investigation against a l
sam00/POC-CVE-2026-54121-Certighost	0	2026-08-03
L0u7r3/certighost	0	2026-08-19	fork and edits from https://github.com/aniqfakhrul/CVE-2026-54121

Detection Rules

Detection available

Community detection & vulnerability-scanning rules aggregated from Sigma and Nuclei templates. Validate and tune to your environment before deploying.