CVE-2026-54119
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 · uneditedLoop with unreachable exit condition ('infinite loop') in Windows Active Directory allows an unauthorized attacker to deny service over a network.
In the news
Third-party coverage- Microsoft July 2026 Patch Tuesday fixes massive 570 flaws, 3 zero-days
- Microsoft CVE Summary - Bleeping Computer
Surfaced from public web coverage — external links open in a new tab.
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 confidenceA vulnerability in Windows Active Directory contains an infinite loop condition that can be triggered by an unauthenticated remote attacker, causing the service to become unresponsive and resulting in denial of service.
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 data< 10.0.14393.9339< 10.0.17763.9020< 10.0.19044.7548< 10.0.19045.7548< 10.0.26100.8875< 10.0.26200.8875< 10.0.28000.2269< 10.0.28000.2525all versions= r2CVSS 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
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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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Confirm the system is a Domain ControllerRun 'Get-Service -Name NTDS' or 'reg query HKLM\SYSTEM\CurrentControlSet\Services\NTDS' on the target Windows host. Also check systeminfo for 'Domain Controller' role.Affected if The NTDS service exists, indicating Active Directory is installed and the system is a Domain Controller.
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Identify the installed Windows versionRun 'winver' or 'systeminfo | findstr /B /C:"OS Version"' to obtain the full Windows build number. Alternatively, run 'ver' at command prompt.Affected if The build number falls within any of these ranges: 10.0.14393.x versions before 9339; 10.0.17763.x versions before 9020; 10.0.19044.x versions before 7548; 10.0.19045.x versions before 7548; 10.0.26100.x versions before 8875; 10.0.26200.x versions before 8875; 10.0.28000.x versions before 2269 or 25
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Check if Active Directory LDAP is network-exposedRun 'netstat -ano | findstr ":389"' or 'netsh advfirewall firewall show rule name=all | findstr /i "LDAP"' to see if port 389 (LDAP) is listening on non-loopback interfaces.Affected if LDAP port 389 is bound to a reachable network interface, making the service accessible to remote attackers.
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Verify LDAP service responsivenessUse ldapsearch or an LDAP client to perform a simple bind to the Domain Controller's LDAP port. Alternatively, run 'repadmin /replsum' to test AD replication responsiveness.Affected if LDAP queries timeout, return errors, or the service becomes unresponsive, which may indicate the infinite loop condition is present.
The environment is affected if the system is a Domain Controller running a Windows version lower than the patched builds listed, and the LDAP service is network-accessible to unauthenticated remote attackers.
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 · scoped10.0.14393.933910.0.17763.902010.0.19044.7548
Apply Microsoft security updates for Windows Active Directory when available; consider network segmentation to limit exposure and implement IDS/IPS rules to detect anomalous LDAP traffic patterns.
Install the corresponding Windows cumulative security update from Microsoft Update (KB reference available at msrc.microsoft.com) that addresses the infinite loop vulnerability in Active Directory
- Identify the exact Windows version by running `winver` or `systeminfo` to confirm the build number
- Determine if the system is on the affected list (Windows 10 1607/1809/21h2/22h2, Windows 11 24h2/25h2/26h1, or Windows Server 2012/2012 R2)
- For Windows 10/11 clients: Open Settings > Update & Security > Windows Update and check for updates; install the latest cumulative security update
- For Windows Server: Use Windows Server Update Services (WSUS), Windows Update for Business, or manually download updates from Microsoft Update Catalog
- Alternatively, run `ms-settings:windowsupdate` from Run dialog to directly open Windows Update
- Verify the installed build matches or exceeds the fixed version: 10.0.14393.9339 (1607), 10.0.17763.9020 (1809), 10.0.19044.7548 (21h2), 10.0.19045.7548 (22h2), 10.0.26100.8875 (24h2), 10.0.26200.8875 (25h2), or 10.0.28000.2269/2525 (26h1)
- For Windows Server 2012/2012 R2: Contact Microsoft Support or check the Microsoft Update Catalog for the specific security bulletin (this version is end-of-life and may require extended security updates)
- After patching, verify Active Directory services are running normally with `Get-Service ADWS` or `net start`
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation4.0 h
- Implementation2.0 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-2026-54119 — 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-2026-54119 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
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