CriticalCVE-2022-26923

Active Directory Domain Services Elevation of Privilege Vulnerability (CVE-2022-26923)

Published 10.05.2022In CISA KEV since 18.08.2022Sources: SingCERT, CVE.org

What is affected, what to do

Active Directory Domain Services Elevation of Privilege Vulnerability

The vulnerability is being actively exploited; treat it as a priority. Update Microsoft Windows 10 Version 1809 to version 10.0.17763.4252, Microsoft Windows Server 2019 to version 10.0.17763.4252, Microsoft Windows Server 2019 (Server Core installation) to version 10.0.17763.4252. Immediate actions, mitigation and detection rules are in the runbook below.

Affected: Microsoft Windows 10 Version 1809 lt 10.0.17763.0..10.0.17763.4252
Microsoft Windows Server 2019 lt 10.0.17763.0..10.0.17763.4252
Microsoft Windows Server 2019 (Server Core installation) lt 10.0.17763.0..10.0.17763.4252
Microsoft Windows 10 Version 1909 lt 10.0.0..10.0.18363.2274
Microsoft Windows 10 Version 21H1 lt 10.0.0..10.0.19043.1706
Microsoft Windows Server 2022 lt 10.0.20348.0..10.0.20348.1668
Microsoft Windows 10 Version 20H2 lt 10.0.0..10.0.19042.1706
Microsoft Windows Server version 20H2 lt 10.0.0..10.0.19042.1706
Microsoft Windows 11 version 21H2 lt 10.0.0..10.0.22000.1817
Microsoft Windows 10 Version 21H2 lt 10.0.19043.0..10.0.19043.1706
Microsoft Windows 10 Version 1507 lt 10.0.10240.0..10.0.10240.19297
Microsoft Windows 10 Version 1607 lt 10.0.14393.0..10.0.14393.5850
Microsoft Windows Server 2016 lt 10.0.14393.0..10.0.14393.5850
Microsoft Windows Server 2016 (Server Core installation) lt 10.0.14393.0..10.0.14393.5850
Microsoft Windows 8.1 lt 6.3.0..6.3.9600.20371
Microsoft Windows Server 2012 R2 lt 6.3.9600.0..6.3.9600.20919
Microsoft Windows Server 2012 R2 (Server Core installation) lt 6.3.9600.0..6.3.9600.20919
Fixed in: Microsoft Windows 10 Version 1809 10.0.17763.4252
Microsoft Windows Server 2019 10.0.17763.4252
Microsoft Windows Server 2019 (Server Core installation) 10.0.17763.4252
Microsoft Windows 10 Version 1909 10.0.18363.2274
Microsoft Windows 10 Version 21H1 10.0.19043.1706
Microsoft Windows Server 2022 10.0.20348.1668
Microsoft Windows 10 Version 20H2 10.0.19042.1706
Microsoft Windows Server version 20H2 10.0.19042.1706
Microsoft Windows 11 version 21H2 10.0.22000.1817
Microsoft Windows 10 Version 21H2 10.0.19043.1706
Microsoft Windows 10 Version 1507 10.0.10240.19297
Microsoft Windows 10 Version 1607 10.0.14393.5850
Microsoft Windows Server 2016 10.0.14393.5850
Microsoft Windows Server 2016 (Server Core installation) 10.0.14393.5850
Microsoft Windows 8.1 6.3.9600.20371
Microsoft Windows Server 2012 R2 6.3.9600.20919
Microsoft Windows Server 2012 R2 (Server Core installation) 6.3.9600.20919

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Metrics

8.8

Priority

XIEM Effective CVSS: highest available CVSS rating from NVD and vendor data.

Source: NVD, CVSS v3

8.8

CVSS v3

Severity High on the scale from 0 to 10.

Source: SingCERT, CVE.org

83.5 %

EPSS score

High — model estimates ≥ 50% chance of real-world exploitation within 30 days.

Source: FIRST EPSS, percentile 99.69

Show all metrics

Severity: Critical
Priority (0–325) The priority score is a consolidated metric that condenses several individual signals into a single, action-guiding ranking: technical severity (CVSS), exploitation likelihood (EPSS), known-exploited status (KEV) and the context of the affected asset. The aim is to answer the only truly important question in vulnerability management: what first? Read in glossary: 224.29 Methodology
Exploit maturity An exploit is code or a technique that specifically uses a concrete vulnerability to force unintended behaviour — such as executing code or escalating privileges. It is the tool that turns a theoretical flaw into a practical attack. Read in glossary: actively exploitedSource: CSA/SingCERT How we classify
XIEM Effective CVSS XIEM® is the tiered managed-security operating model from NEOSEC and a registered trademark of NEOSEC GmbH. It extends classic SIEM — the central collection, normalisation and correlation of security-relevant events — with endpoint forensics, network visibility and deception technology, and consolidates them into three building tiers: Sentry, Orchestrate and Command. Read in glossary: 8.8 Methodology
CVSS v3 CVSS is the globally established, open standard for assessing the technical severity of a vulnerability on a scale from 0 to 10. It describes how easily a flaw can be exploited and what damage it can cause — but not how likely its actual exploitation is. CVSS and the complementary EPSS deliberately answer different questions. Read in glossary: 8.8
EPSS score The EPSS score is the absolute model output for an individual vulnerability: the estimated probability of real-world exploitation within the next 30 days, expressed as a value between 0 and 1 (i.e. 0 % to 100 %). A score of 0.42 means „the model estimates a 42 % chance of real-world exploitation within 30 days“. Read in glossary: 83.5 %; High — model estimates ≥ 50% chance of real-world exploitation within 30 days.
EPSS percentile The EPSS percentile is the relative position of a vulnerability within all EPSS-scored CVEs, expressed as a value between 0 and 1. A percentile of 0.90 means „this CVE has a higher EPSS score than 90 % of all other scored CVEs“. Unlike the EPSS score, it is not a probability — but a positioning within a ranking. Read in glossary: 99.69; Critical — this CVE ranks in the top fifth of all CVEs scored today (rank ≥ 80%).
KEV status The KEV catalogue is a list maintained by the US authority CISA of vulnerabilities for which active exploitation in the wild has been confirmed. It answers not the question „how severe?“ but „is it already being attacked?“ — thereby sharply prioritising patching. Read in glossary: Actively exploited
Published: 10.05.2022
In CISA KEV since The KEV catalogue is a list maintained by the US authority CISA of vulnerabilities for which active exploitation in the wild has been confirmed. It answers not the question „how severe?“ but „is it already being attacked?“ — thereby sharply prioritising patching. Read in glossary: 18.08.2022
CISA assessment (SSVC): Exploitation: active · not automatable · Technical impact: total; Source: CISA Vulnrichment, as of 4 February 2025
CWE CWE is a catalogue of typical weakness types in software and hardware — such as flawed input validation, unsafe memory handling or poor authentication. Where a CVE names a concrete vulnerability in a concrete product, a CWE describes the underlying class of defect. Read in glossary: CWE-295

Response and mitigation

Why act now?

Prioritisation rationale

“Certifried” lets any authenticated domain user, with no user interaction, register a computer account, impersonate a domain controller via AD CS and obtain full domain compromise. Public tooling such as Certipy automates the entire chain, so exploitation likelihood is very high and it is a common privilege-escalation step after an initial phishing foothold. CISA does not flag known ransomware use, but that offers little comfort: any organisation running AD CS with the default machine account quota is exposed. For KRITIS/NIS2 environments with AD CS, treat this as a top-priority Tier-0 risk; without AD CS the practical risk drops sharply, but patching remains mandatory.

01
Runbook step 1
Immediate response (0-24 h)
- Patch domain controllers and AD CS certificate authorities first, then the rest of the fleet. Minimum builds per context: Windows 10 1607 / Server 2016 → 10.0.14393.5850, Windows 10 1809 / Server 2019 → 10.0.17763.4252, 20H2 → 10.0.19042.1706, 21H1/21H2 → 10.0.19043.1706, Windows 11 21H2 → 10.0.22000.1817. For Server 2022 and other unlisted versions: patch available from the vendor — look up the exact version in the vendor advisory.
- Verify the strong certificate mapping hardening (KB5014754): on every DC, set or confirm StrongCertificateBindingEnforcement under HKLM\SYSTEM\CurrentControlSet\Services\Kdc = 2 (full enforcement). A value of 0 neutralises the fix.
- Set ms-DS-MachineAccountQuota to 0 on the domain object so regular users can no longer create computer accounts — the standard entry point of this attack.
- Audit recently created computer accounts: disable and preserve any account whose ms-DS-CreatorSID is a standard user, or whose dNSHostName matches a DC or Tier-0 server.
- Review machine certificates issued in the exposure window: search the CA database for “Machine”/“Computer” template certificates whose subject/SAN carries a DC name but were not requested by that DC's account. Revoke hits.
- If compromise is suspected, reset the KRBTGT password twice and rotate privileged credentials — successful exploitation typically ends in DCSync.
02
Runbook step 2
Mitigation layers
- IAM / least privilege: restrict “Validated write to DNS host name” and “Write all properties” on computer objects to Tier-0 admins; review delegations to helpdesk groups.
- AD CS hardening: limit enrollment on the “Machine” template to groups that actually need it (dedicated server groups instead of “Domain Computers”); disable unused templates. Audit templates for ESC misconfigurations with Certipy or PSPKIAudit.
- Network segmentation: allow RPC/DCOM (TCP 135 plus dynamic range) and HTTP web enrollment (TCP 80/443, /certsrv) to the CA only from management and server segments; block client VLANs where autoenrollment is not required.
- Kerberos PKINIT: allow certificate logon only for accounts that need it (smartcard users); alert on unexpected PKINIT requests for DC accounts.
- Tiering: treat DCs and CA servers as Tier 0; deny interactive/RDP logon for non-Tier-0 accounts via GPO.
03
Runbook step 3
Detection rules
- Computer account created by a standard user: Security Event 4741 on DCs where SubjectUserName is not an admin or domain-join service account. Sigma shape: EventID: 4741 AND NOT SubjectUserName|in: <join_accounts>.
- dNSHostName / SPN tampering: Event 5136 (Directory Service Changes, requires SACL) or 4742 with changed DnsHostName/ServicePrincipalNames. KQL: SecurityEvent | where EventID == 5136 and EventData has "dNSHostName" — then compare the new value against DC names.
- Certificate issuance on the CA: Events 4886/4887 where the requester is a non-DC computer account ($) but the subject contains a DC FQDN. A 4741 → 5136 → 4887 sequence within minutes is a strong signal.
- PKINIT logon as a DC: Event 4768 with PreAuthType = 16/17 (certificate-based) for a DC account from an IP that is not the DC; also KDC System-log events 39/40/41 flagging weak or mismatched certificate mappings.
- DCSync follow-on: Event 4662 with replication GUIDs 1131f6aa-…/1131f6ad-… from a non-DC source; Zeek dce_rpc showing DRSGetNCChanges from client segments.

Detection rules

No NEOSEC detection rule is available for this vulnerability yet.

Classification under NIS2 and CRA

Rule-based classification from exploitation status and severity. It does not replace a case-by-case assessment.

NIS2 NIS2 is EU Directive (EU) 2022/2555 to raise the level of cybersecurity across the Union. It substantially broadens obligations compared with the first NIS directive: more sectors, mandatory risk management, staged reporting duties and personal accountability of senior management. Read in glossary: Actively exploited: treat the vulnerability as a priority in vulnerability handling under Art. 21(2)(e) NIS2. If it is exploited in your environment, check the reporting obligation under Art. 23 (early warning within 24 hours).
CRA The CRA is EU Regulation (EU) 2024/2847 setting horizontal cybersecurity requirements for „products with digital elements“ — from industrial controllers and software to connected consumer devices. For the first time manufacturers must ensure security across the entire product lifecycle, handle vulnerabilities and provide security updates. Read in glossary: Since 11.09.2026, manufacturers of affected products with digital elements must report actively exploited vulnerabilities under Art. 14 CRA, with an early warning within 24 hours via ENISA's single reporting platform.
ISO/IEC 27001 ISO/IEC 27001 is the internationally leading standard for an information security management system (ISMS). It describes a risk-based, process-oriented framework to systematically plan, implement, review and improve information security. Read in glossary: Control A.8.8, management of technical vulnerabilities: assess relevance to your systems, plan remediation and keep evidence.

Description

Active Directory Domain Services Elevation of Privilege Vulnerability

Source: CSA/SingCERT, cvelistv5, NVD (NIST), CISA KEV Catalog, CVE.org (MITRE)

Affected products

The following versions are affected. Older releases of the same product line are also vulnerable unless stated otherwise.

Affected products
		Affected versions	Fixed in
Microsoft	Windows 10 Version 1507	`10.0.10240.0 – < 10.0.10240.19297`	`10.0.10240.19297`
Microsoft	Windows 10 Version 1607	`10.0.14393.0 – < 10.0.14393.5850`	`10.0.14393.5850`
Microsoft	Windows 10 Version 1809	`10.0.17763.0 – < 10.0.17763.4252`	`10.0.17763.4252`
Microsoft	Windows 10 Version 1909	`10.0.0 – < 10.0.18363.2274`	`10.0.18363.2274`
Microsoft	Windows 10 Version 20H2	`10.0.0 – < 10.0.19042.1706`	`10.0.19042.1706`
Microsoft	Windows 10 Version 21H1	`10.0.0 – < 10.0.19043.1706`	`10.0.19043.1706`
Microsoft	Windows 10 Version 21H2	`10.0.19043.0 – < 10.0.19043.1706`	`10.0.19043.1706`
Microsoft	Windows 11 version 21H2	`10.0.0 – < 10.0.22000.1817`	`10.0.22000.1817`
Microsoft	Windows 8.1	`6.3.0 – < 6.3.9600.20371`	`6.3.9600.20371`
Microsoft	Windows Server 2012 R2	`6.3.9600.0 – < 6.3.9600.20919`	`6.3.9600.20919`
Microsoft	Windows Server 2012 R2 (Server Core installation)	`6.3.9600.0 – < 6.3.9600.20919`	`6.3.9600.20919`
Microsoft	Windows Server 2016	`10.0.14393.0 – < 10.0.14393.5850`	`10.0.14393.5850`
Microsoft	Windows Server 2016 (Server Core installation)	`10.0.14393.0 – < 10.0.14393.5850`	`10.0.14393.5850`
Microsoft	Windows Server 2019	`10.0.17763.0 – < 10.0.17763.4252`	`10.0.17763.4252`
Microsoft	Windows Server 2019 (Server Core installation)	`10.0.17763.0 – < 10.0.17763.4252`	`10.0.17763.4252`
Microsoft	Windows Server 2022	`10.0.20348.0 – < 10.0.20348.1668`	`10.0.20348.1668`
Microsoft	Windows Server version 20H2	`10.0.0 – < 10.0.19042.1706`	`10.0.19042.1706`

Vendors and products

Affected operating systems

Affected operating systems

Windows	microsoft	windows_10_1507	—
Windows	microsoft	windows_10_1607	—
Windows	microsoft	windows_10_1809	—
Windows	microsoft	windows_10_1909	—
Windows	microsoft	windows_10_20h2	—
Windows	microsoft	windows_10_21h1	—
Windows	microsoft	windows_10_21h2	—
Windows	microsoft	windows_11_21h2	—
Windows	microsoft	windows_8.1	—
Windows	microsoft	windows_rt_8.1	—
Windows	microsoft	windows_server_2012	`r2`
Windows	microsoft	windows_server_2016	—
Windows	microsoft	windows_server_2019	—
Windows	microsoft	windows_server_2022	—

Weakness classes (CWE)

CWE-295Improper Certificate Validation
Base
The product does not validate, or incorrectly validates, a certificate.
Entry at MITRE CWE-295

Public exploit references

Publicly reported proof-of-concepts, exploit modules and detection templates for this vulnerability. NEOSEC links to the original sources only and does not provide any exploit code.

Public exploit references

CISA KEV Catalog	CISA Known Exploited Vulnerability (opens in a new tab)cisa.gov	actively exploited	18.08.2022
CSA/SingCERT	Active Exploitation of Vulnerabilities in Apple, Google, Microsoft, Palo Alto and SAP products (opens in a new tab)CSA/SingCERT	actively exploited	23.08.2022
PoC-in-GitHub (nomi-sec)	CVE-2022-26923 (opens in a new tab)github.com	PoC (publicly reported)reported, not verified	29.05.2026

References & sources

Microsoft Security Update GuideActive Directory Domain Services Elevation of Privilege VulnerabilityVendor advisory, Patch, Vendor advisory
portal.msrc.microsoft.comen-US/security-guidance/advisory/CVE-2022-26923x_refsource_MISC, x_transferred, Patch, Vendor advisory
cisa.govknown-exploited-vulnerabilities-catalog?field_cve=CVE-2022-26923government-resource, US government resource

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What is affected, what to do

Metrics

Response and mitigation

Prioritisation rationale

Immediate response (0-24 h)

Mitigation layers

Detection rules

Detection rules

Classification under NIS2 and CRA

Description

Affected products

Vendors and products

Affected operating systems

Weakness classes (CWE)

Public exploit references

References & sources