Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain
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AccessReach DHCP server via LAN segment or relay agent
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ExploitSend crafted DHCP packet with malformed option/length field
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ExecutionTrigger out-of-bounds read in server parser
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ImpactLeak adjacent memory contents in DHCP response
Vulnerability Assessment
| Weakness |
CWE
ASVS 5.0
V15 - Secure Coding and Architecture Bounds checking, read limits
MITRE ATT&CK
1 technique across 1 tactic: Collection The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. |
| Exploitation Conditions | Exploitation requires the target Windows system to have the DHCP Server role explicitly installed and running - this is a non-default configuration absent from standard workstations and servers without the role deployed. The attacker must reach UDP port 67 on the DHCP server, either via the same local network segment or through a DHCP relay agent forwarding requests across routed segments. Per the CVSS vector (PR:N), no authentication credentials are required; any network-reachable host can send DHCP packets to trigger the read. Impact is strictly limited to information disclosure (C:H/I:N/A:N) with no confirmed code execution or availability disruption path. DHCP servers are typically internal infrastructure not exposed to the public internet, which substantially narrows the realistic attack population to internal or relay-proxied adversaries. |
| Impact | Microsoft's CVSS 7.5 vector (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N) accurately captures the zero-authentication attack surface of the DHCP protocol, though real-world risk is tempered by deployment scope: only systems with the DHCP Server role explicitly installed are vulnerable, which excludes most Windows workstations and the large majority of servers without the role. DHCP traffic is normally constrained to local network segments, though DHCP relay agents can project the attack surface across routed environments. The confidentiality impact is rated High with no integrity or availability component, consistent with a read-only memory-disclosure primitive. EPSS at 0.77% (53rd percentile) reflects a low mass-exploitation probability, and the absence of both a CISA KEV listing and any public proof-of-concept further reduces urgency. This is best characterized as a moderate operational priority: DHCP servers should be patched promptly given the zero-authentication exposure, but this does not carry the same urgency as a code-execution primitive. |
| Exploit ScenarioDerived | An attacker with access to the same network segment as a Windows DHCP Server - or with the ability to route packets through a DHCP relay agent - sends a specially crafted DHCP discover or request packet containing a malformed option or oversized length field. The DHCP Server's packet-parsing routine performs a read beyond the allocated buffer boundary (CWE-125), and the leaked memory contents are returned in the DHCP response or error reply. The disclosed data could include heap layout artifacts or other in-memory data useful for further attack chaining, though no public exploit or confirmed chaining technique has been identified. |
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Alert meAnalysisAIv2 – Sep 10, 2026
Out-of-bounds memory read in the Windows DHCP Server service exposes potentially sensitive server memory to unauthenticated remote attackers who send specially crafted DHCP packets. The flaw (CWE-125) spans Microsoft Windows Server 2012 through 2025 and select Windows 10 builds where the DHCP Server role is installed, with Microsoft assigning CVSS 7.5 reflecting full network accessibility and zero authentication requirement. No active exploitation or public proof-of-concept has been identified; EPSS sits at 0.77% (53rd percentile) and a vendor-supplied patch is available.
Earlier versions of this analysis (1)
Out-of-bounds read in Windows DHCP Server (CWE-125) allows unauthenticated remote attackers to disclose server memory contents over the network. The vulnerability spans all major Windows Server releases from 2012 through 2025 as well as Windows 10 versions 1607 and 1809. CVSS 5.9 (AV:N/AC:H/PR:N/UI:N) reflects network reachability without authentication but with elevated attack complexity, suggesting specific packet construction or timing requirements; no public exploit or active KEV listing has been identified at time of analysis.
RemediationAI
Apply the Microsoft security update through Windows Update, WSUS, or the Microsoft Update Catalog. Fixed build versions per platform derived from EUVD data are: Windows Server 2012 → 6.2.9200.26349, Windows Server 2012 R2 → 6.3.9600.23397, Windows Server 2016 and Windows 10 1607 → 10.0.14393.9512, Windows Server 2019 and Windows 10 1809 → 10.0.17763.9245, Windows Server 2022 → 10.0.20348.5622, and Windows Server 2025 → 10.0.26100.33438. Consult the Microsoft Security Response Center at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-69803 for update package links. Where immediate patching is not feasible, restrict inbound UDP ports 67 and 68 at network perimeter and inter-VLAN boundaries to limit DHCP server exposure to trusted segments only - note this does not mitigate threats from already-compromised internal hosts. Removing the DHCP Server role from systems that do not require it eliminates the attack surface entirely.
Affected VersionsENISA
Affected Packages
Source: OSV (Open Source Vulnerabilities)
Affects your stack
Affects 13 packages in euvd
Checking this CVE against your own stacks and servers is part of the Basic plan and up.
Technical ContextAI · show details
CWE-125 (Out-of-Bounds Read) occurs when a memory read operation accesses data beyond the bounds of an allocated buffer. In the Windows DHCP Server context, DHCP clients communicate with the server over UDP ports 67/68 without any prior authentication - the server must process requests from arbitrary hosts to fulfill its function. A malformed or crafted DHCP option field or packet length value could cause the server's packet-parsing logic to read past a legitimate buffer boundary, leaking adjacent heap or stack memory in response data. CPE strings confirm the vulnerable component is shared across Windows Server 2012 (build 6.2.9200), Windows Server 2012 R2 (6.3.9600), Windows Server 2016 and Windows 10 1607 (10.0.14393), Windows Server 2019 and Windows 10 1809 (10.0.17763), Windows Server 2022 (10.0.20348), and Windows Server 2025 (10.0.26100). The CVE was reported by secure@microsoft.com, indicating internal or coordinated disclosure.
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Severity by source
AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
DHCP processes unauthenticated UDP packets from any network-reachable host; relay-agent reach justifies AV:N; impact is read-only memory disclosure with no integrity or availability component.
Primary rating from NVD.
CVSS VectorNVD
Lifecycle Timeline
5DescriptionNVD
Out-of-bounds read in Windows DHCP Server allows an unauthorized attacker to disclose information over a network.
Executive ViewAI
Windows DHCP Server running on Windows Server 2012 through 2025 and select Windows 10 builds contains an out-of-bounds memory read vulnerability (CVE-2026-69803, CVSS 7.5) that permits unauthenticated remote attackers to access potentially sensitive server memory via specially crafted DHCP packets. No public exploit identified at time of analysis, though the vulnerability affects a critical network service accessible to all connected devices. Organizations operating DHCP servers must prioritize patching to prevent information disclosure that could expose domain credentials, configuration data, and other sensitive server state.
Apply vendor patch.
Threat Intelligence Overview
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
Information disclosure occurs when an application unintentionally exposes sensitive data that aids attackers in reconnaissance or directly compromises security.
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EUVD-2026-73574
GHSA-gwjv-mg5h-rf53
NVD
CVE.org
EPSS
Vulnrichment
VulDB
Exploit-DB