Critical

Windows DHCP Client Service Remote Code Execution

IdentifiersCVE-2026-44815CWE-121· Stack-based Buffer Overflow

CVE-2026-44815 is a critical remote code execution vulnerability in the Windows DHCP Client caused by a stack-based buffer overflow. Microsoft identifies the flaw as CWE-121. The issue is triggered when a vulnerable Windows DHCP client processes crafted data returned by a malicious DHCP server. The provided content further indicates that the crafted data is not used unless the DhcpGetOriginalSubnetMask API is called, making that API path central to exploitation. Microsoft’s advisory states that an attacker can exploit the vulnerability by setting up a DHCP server on the network and responding to a DHCP client request with specially crafted DHCP information, leading to memory corruption and potential code execution in the DHCP Client service context.

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ANALYST BRIEF

Impact, mitigation & remediation

What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.

Impact

What an attacker gets, and what they’ve been doing with it.

Successful exploitation allows remote code execution against a vulnerable Windows system over the network. According to the supplied CVSS vector and advisory details, the vulnerability can be exploited with no privileges required and no user interaction, with high impact to confidentiality, integrity, and availability. Because the DHCP Client runs broadly across Windows installations, exploitation could provide a high-value path to full compromise of affected endpoints.

Mitigation

If you can’t patch tonight, do this now.

Reduce exposure by keeping the DHCP Client service enabled for normal network configuration while avoiding use of the DhcpGetOriginalSubnetMask API where possible. Review dependent applications and components for use of that API, and reconfigure or update them to eliminate that call path until patches are fully deployed. Follow Microsoft product guidance for any additional defensive configuration related to the affected DHCP Client behavior.

Remediation

Patch, then assume compromise.

Apply Microsoft’s official security update for CVE-2026-44815 to affected Windows systems. In addition, review applications or components that call the DhcpGetOriginalSubnetMask API and update or reconfigure them to avoid calling that API where possible, as Microsoft states the crafted DHCP data is not used unless that API is invoked.

PUBLIC EXPLOITS

Exploits

No public exploits tracked yet. Mallory keeps watching.

VALID 0 / 0 TOTALView more in app

No public exploit code observed for this vulnerability.

ACTIVITY FEED

Recent activity

6 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.

6 SOURCESView more in app

cyberthroneNews

Jun 10, 2026

Microsoft Patch Tuesday - June 2026 - TheCyberThrone

A critical stack-based buffer overflow remote code execution vulnerability in the Windows DHCP Client.

security affairsNews

Jun 9, 2026

Microsoft Releases Record-Breaking Patch Tuesday With 208 CVEs

A critical remote code execution vulnerability in the Windows DHCP Client Service that may allow unauthenticated remote code execution without user interaction.

malware newsNews

Jun 9, 2026

Microsoft Patch Tuesday for June 2026 - Snort rules and prominent vulnerabilities - Malware News - Malware Analysis, News and Indicators

A critical remote code execution vulnerability in Windows DHCP Client caused by a stack-based buffer overflow.

dark readingNews

Jun 9, 2026

Blame AI: Patch Tuesday Hits Record 206 CVEs

A critical vulnerability in the Windows DHCP Client service with broad exposure because the service runs on virtually every Windows endpoint.

+1 more in the timeline

What this page doesn’t show

The version that knows your environment.

This page is what’s public. Mallory adds the parts that aren’t: which of your assets are affected, which adversaries are exploiting it right now, which detections to deploy, and what to do tonight.

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Exposure mapping

Query your assets running an affected version, and investigate the blast radius.

Threat actor evidence

Every observed campaign linking this CVE to a named adversary.

Associated malware

Malware families riding this exploit, with evidence and IOCs.

Detection signatures

YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.

Vendor-by-vendor mapping

Cross-references every affected SKU, including bundled OEM variants.

Social activity1

Community discussion across Reddit, Mastodon, and other social sources.

EXTERNAL REFERENCES

MITRE CVE

cve.org · CVE-2026-44815

NVD

nvd.nist.gov/vuln/detail/CVE-2026-44815

MITRE CWE · CWE-121

Stack-based Buffer Overflow

msrc.microsoft.com

msrc.microsoft.com/update-guide/vulnerability/CVE-2026-44815