CVE-2025-27740
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedWeak authentication in Windows Active Directory Certificate Services allows an authorized attacker to elevate privileges over a network.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · moderate confidenceThis vulnerability in Windows Active Directory Certificate Services involves weak authentication mechanisms that allow an already authorized attacker to escalate their privileges. The attacker leverages inadequate authentication validation within AD CS to gain higher-level access than their current authorization permits, potentially achieving domain administrator-level privileges.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE dataall versions= r2all versions= r2< 10.0.14393.7969< 10.0.17763.7136< 10.0.20348.3453< 10.0.25398.1551< 10.0.26100.3775CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Verify AD CS role is installedRun 'Get-WindowsFeature -Name AD-Certificate' in PowerShell on the server. If InstallState shows 'Installed', the server runs AD Certificate Services.Affected if AD CS is installed and the Windows Server version falls within the affected ranges (2008/2012 all versions, 2016 < 10.0.14393.7969, 2019 < 10.0.17763.7136, 2022 < 10.0.20348.3453, 2022 23h2 < 10.0.25398.1551, 2025 < 10.0.26100.3775).
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Confirm Windows Server versionRun '[System.Environment]::OSVersion.Version' or '(Get-ItemProperty 'HKLM:\SOFTWARE\Microsoft\Windows NT\CurrentVersion') | Select-Object CurrentBuild, DisplayVersion' to get the exact build number.Affected if The build number is lower than the threshold for the respective Windows Server version listed in the affected products.
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Identify certificate enrollment endpointsRun 'certutil -csInfo' to list Certificate Services endpoints, then inspect 'netsh http show urlacl' for enrollment URL ACLs. Check if HTTP-based enrollment (non-TLS) is enabled.Affected if AD CS enrollment endpoints accept weak authentication methods (such as NTLM without TLS or certificate-based authentication with weak validation).
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Enumerate certificate templates for privilege escalationOpen 'certtmpl.msc' or run 'Get-ADObject -LDAPFilter '(objectClass=pkITemplate)' -Properties * | Select-Object name, msPKI-Certificate-Name-Flag, pKIExtendedKeyUsage' to list templates.Affected if Templates exist that allow low-privilege users to enroll for certificates with flags or extensions enabling domain privilege escalation (such as authentication or smart card logon purposes).
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Review enrollment permissions on templatesRun 'Get-Acl 'AD:CN=Certificate Templates,CN=Public Key Services,CN=Services,CN=Configuration,DC=YOURDOMAIN' | Select-Object AccessToString' or use certtmpl.msc to view security descriptors on templates.Affected if Certificate templates grant enrollment rights to broad groups (such as Domain Users or Authenticated Users) without appropriate restrictions, enabling privilege escalation.
The server is affected if AD CS is installed, the Windows version is below the specified build thresholds, and weak authentication or overly permissive certificate template enrollment permissions are present.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped10.0.14393.796910.0.17763.713610.0.20348.3453
Apply Microsoft security updates for Active Directory Certificate Services immediately. Review certificate templates and enrollment policies for overly permissive access controls that could compound this vulnerability.
Apply the Microsoft security update for CVE-2025-27740 to reach the minimum build numbers: Server 2016 -> 10.0.14393.7969, Server 2019 -> 10.0.17763.7136, Server 2022 -> 10.0.20348.3453, Server 2022 23h2 -> 10.0.25398.1551, Server 2025 -> 10.0.26100.3775; Server 2008/2012 require migration to suppor
- Identify the Windows Server version running Active Directory Certificate Services (AD CS) using `winver` or `systeminfo`
- Determine the current build number (e.g., `winver` shows 10.0.XXXXX.XXXX)
- For Windows Server 2008/2012 (all versions): These are end-of-life; migrate to a supported Windows Server version
- For Windows Server 2016 and later: Apply the cumulative security update for the respective month/year that addresses CVE-2025-27740 via Windows Update, WSUS, or Microsoft Update Catalog
- After installation, restart the server if prompted
- Verify the fix by checking the installed updates: Run `winver` to confirm the build number meets or exceeds 10.0.14393.7969 (Server 2019), 10.0.17763.7136 (Server 2019), 10.0.20348.3453 (Server 2022), 10.0.25398.1551 (Server 2022 23h2), or 10.0.26100.3775 (Server 2025)
- If AD CS is installed, verify the service starts successfully after reboot
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation4.0 h
- Implementation8.0 h
- Testing6.0 h
- Review / QA3.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2025-27740 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2025-27740 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
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