CVE-2026-49181: Microsoft Windows DHCP Client integer underflow privilege escalation

CVE-2026-49181 · Severity: high · CVSS 7.5 · Published 2026-07-14

A vulnerability in the Windows DHCP Client allows an unauthorized attacker to gain elevated privileges over a network. The DHCP Client is a standard component that allows Windows computers to automatically receive network configuration settings. If exploited, an attacker could potentially access sensitive information or gain higher-level control over the affected system without needing physical access or user interaction.

Technologies: Microsoft Windows Server 2012 R2, Microsoft Windows 10, Microsoft Windows Server 2012, Microsoft Windows Server 2016, Microsoft Windows Server 2019. Vendors: Microsoft.

Quick answers

Is CVE-2026-49181 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-49181 being exploited in the wild.
How severe is CVE-2026-49181?
High severity, with a CVSS score of 7.5, published 14 July 2026.
Which products and versions are affected?
Microsoft Windows 10 10.0.14393.0 to 10.0.14393.9339; Microsoft Windows Server 2012 6.2.9200.0 to 6.2.9200.26226 / 6.3.9600.0 to 6.3.9600.23291; Microsoft Windows Server 2016 10.0.14393.0 to 10.0.14393.9339 / 10.0.17763.0 to 10.0.17763.9020.
Is there a fix for CVE-2026-49181?
A patch was published on 2026-07-14: Security updates released by Microsoft. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-49181 attacked?
It is attacked over the network, in an operating system.
Am I affected by CVE-2026-49181?
Check whether you run Microsoft Windows Server 2012 R2, Microsoft Windows 10, Microsoft Windows Server 2012 or one of the others listed at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

An integer underflow (CWE-191) exists in the Windows DHCP Client component. The vulnerability is triggered when the client processes specially crafted DHCP packets, leading to a wrap or wraparound condition. An unauthenticated attacker can exploit this over the network without any user interaction to achieve an elevation of privilege. While the CVSS vector indicates high confidentiality impact, the primary risk is the unauthorized escalation of rights on the target system. Microsoft has released security updates to address this issue across various versions of Windows 10 and Windows Server.

Affected products

  • Microsoft Windows 10 Version 1607 10.0.14393.0 to 10.0.14393.9339
  • Microsoft Windows 10 Version 1809 10.0.17763.0 to 10.0.17763.9020
  • Microsoft Windows Server 2012 / 2012 R2 6.2.9200.0 to 6.2.9200.26226 / 6.3.9600.0 to 6.3.9600.23291
  • Microsoft Windows Server 2016 / 2019 10.0.14393.0 to 10.0.14393.9339 / 10.0.17763.0 to 10.0.17763.9020

Timeline

  • 2026-07-14: disclosed: Initial publication of the CVE record and Microsoft advisory.
  • 2026-07-14: patched: Security updates released by Microsoft.

References

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