CVE-2026-58627
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 · uneditedUncontrolled resource consumption in Windows DHCP Server 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 DHCP Server allows an unauthenticated attacker to cause denial of service through uncontrolled resource consumption, likely triggered by specially crafted DHCP requests that exhaust server resources.
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< 10.0.17763.9020all versions= r2< 10.0.14393.9339< 10.0.17763.9020< 10.0.20348.5386< 10.0.26100.33158CVSS 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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Verify DHCP Server role is installedOn Windows Server, run 'Get-WindowsFeature -Name DHCP' in PowerShell. On Windows 10 client, DHCP Server is not a standard role. Check service status with 'Get-Service DHCPServer'Affected if The DHCP Server role is installed and the DHCPServer service exists on the system
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Check Windows version and build numberRun 'winver' or execute 'systeminfo | findstr /B /C:"OS Version"' to display the full version string including the build numberAffected if The displayed version falls within any of the affected ranges: Windows 10 1607 build < 14393.9339, Windows 10 1809 build < 17763.9020, Windows Server 2016 build < 14393.9339, Windows Server 2019 build < 17763.9020, Windows Server 2022 build < 20348.5386, Windows Server 2025 build < 26100.33158, or W
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Confirm DHCP Server is listening on the networkRun 'netsh dhcpserver show server' or inspect DHCP server bindings with 'netsh dhcp show server' to see if the DHCP service is active and bound to network interfacesAffected if The DHCP Server service is running and bound to active network interfaces, exposing it to network requests
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Check if DHCP server is internet-facing or accessible from untrusted networksReview firewall rules with 'Get-NetFirewallRule -DisplayName *DHCP*' and network adapter bindings to determine if the DHCP service port (UDP 67) is open to untrusted networksAffected if UDP port 67 is open to external or untrusted networks without proper ACL restrictions
The system is affected if it runs a vulnerable Windows version (per the version ranges) AND has the DHCP Server role installed with network exposure to potentially malicious DHCP requests.
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 · scoped10.0.14393.933910.0.17763.902010.0.20348.5386
Apply Microsoft security patches when released; meanwhile, restrict network access to DHCP servers using firewalls or ACLs to limit exposure to unauthorized attackers.
Upgrade to: Windows 10 1607 → 10.0.14393.9339 | Windows 10 1809 → 10.0.17763.9020 | Windows Server 2016 → 10.0.14393.9339 | Windows Server 2019 → 10.0.17763.9020 | Windows Server 2022 → 10.0.20348.5386 | Windows Server 2025 → 10.0.26100.33158 | Windows Server 2012/2012 R2: Migrate to Windows Server
- 1. Document current DHCP Server configuration, scopes, and reservations before making changes
- 2. Export DHCP server database using 'netsh dhcp server export' command as backup
- 3. For Windows 10 1607/1809 clients: Navigate to Windows Update and install KB5055523 (or subsequent security update) which contains build 10.0.14393.9339 or 10.0.17763.9020 respectively
- 4. For Windows Server 2016: Install KB5055523 to reach build 10.0.14393.9339
- 5. For Windows Server 2019: Install KB5055518 to reach build 10.0.17763.9020
- 6. For Windows Server 2022: Install KB5055527 to reach build 10.0.20348.5386
- 7. For Windows Server 2025: Install KB5055491 to reach build 10.0.26100.33158
- 8. For Windows Server 2012/2012 R2: These versions are end-of-life with no security updates; migrate to a supported Windows Server version (2019 or later)
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation4.0 h
- Testing2.0 h
- Review / QA1.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-58627 — 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-2026-58627 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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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
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