Skip to main content

Windows DHCP Server EUVDEUVD-2026-73280

| CVE-2026-77891 MEDIUM
Out-of-bounds Read (CWE-125)
2026-09-08 secure@microsoft.com GHSA-w3g8-qp49-28qx
6.4
CVSS 3.1 · Vendor: microsoft
View

Attack ChainAIDerived

Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain

  1. Access
    Obtain local admin access to DHCP server host
  2. Delivery
    Interact with DHCP Server service to trigger OOB read
  3. Exploit
    Leak heap/stack memory to defeat ASLR
  4. Execution
    Construct memory corruption primitive from read primitive
  5. Impact
    Execute arbitrary code as SYSTEM

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

The Windows DHCP Server role must be installed and actively running on the target system - systems that do not have this role enabled are not affected. The attacker must have local, authenticated access with high-level privileges (PR:H per CVSS), consistent with a local administrator or a service account with equivalent rights. High attack complexity (AC:H) imposes additional constraints, such as specific memory layout conditions, timing requirements, or multi-step preparation that cannot be reliably automated in a generic exploit. Limiting factors: exploitation is local-only (AV:L) and cannot be triggered remotely over the network; the attacker must already possess high privileges, meaning the DHCP server must first be compromised at an administrative level; the DHCP Server role must be present; and the high complexity further reduces exploitability. The vulnerability does not enable privilege escalation from unprivileged users and does not provide an initial network foothold.

Impact

The CVSS 6.4 score is appropriate and accurately reflects highly constrained exploitation conditions: AV:L (local access only, not network-reachable), AC:H (high complexity - attacker must overcome timing, memory layout, or other technical hurdles), and PR:H (attacker must already hold elevated/administrative privileges on the target server). The impact triad of C:H/I:H/A:H reflects worst-case post-exploitation outcomes if the memory corruption is successfully leveraged for code execution, potentially at SYSTEM level. No EPSS data is provided; given the absence of any KEV listing and no public POC, exploitation probability is assessed as low at this time. Real-world risk priority is moderate: patch within normal monthly update cadence rather than emergency response. The primary exposure scenario is an insider threat or a compromised admin account on a DHCP server - not an opportunistic network attacker. The 'Information Disclosure' tag in the input understates the actual confirmed impact (code execution), while 'Buffer Overflow' is a loose characterization of CWE-125 (Out-of-Bounds Read).

Exploit ScenarioDerived

An authorized attacker - such as a compromised administrator account or a malicious insider - with local access to a Windows Server running the DHCP Server role crafts a specific input or sequence of operations that triggers an out-of-bounds read in the DHCP service, leaking memory layout information sufficient to defeat ASLR. The attacker uses the disclosed pointer values to construct a follow-on exploitation primitive, ultimately achieving arbitrary code execution in the context of the DHCP Server service, which typically runs as SYSTEM. High attack complexity means the attacker must account for memory layout variability and likely requires multiple attempts or precise timing. No public POC has been identified.

This Month Plan within 30 days. Why: MEDIUM severity (CVSS 4.0-6.9).
Patch available 0.2% exploitation probability (EPSS)

Get an e-mail when this CVE is exploited, patched or re-scored. Free account.

Alert me

AnalysisAIv1 – Sep 08, 2026

Local code execution in Windows DHCP Server affects all major Windows Server versions from 2012 through 2025, exploitable by an authorized attacker with high-level local privileges. The vulnerability stems from an out-of-bounds read (CWE-125) in the DHCP Server role that, despite its read-class root cause, is confirmed by Microsoft to enable code execution - suggesting the OOB read yields a usable memory corruption primitive. Exploitation is substantially constrained by requiring local access, high attack complexity, and high privileges (PR:H/AC:H/AV:L), and no public exploit or active exploitation has been identified.

RemediationAI

Apply the Microsoft-issued patches for this vulnerability via Windows Update or WSUS. Fixed builds confirmed from EUVD data: Windows Server 2025 → 10.0.26100.33438; Windows Server 2022 → 10.0.20348.5622; Windows Server 2019 and Windows 10 1809 → 10.0.17763.9245; Windows Server 2016 and Windows 10 1607 → 10.0.14393.9512; Windows Server 2012 R2 → 6.3.9600.23397; Windows Server 2012 → 6.2.9200.26349. Full advisory and patch download links are at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-77891. As a compensating control prior to patching, strictly limit local logon and Remote Desktop access to DHCP servers to the minimum required administrator accounts, enforce just-in-time access for administrative sessions, and audit for unauthorized local privilege escalation on DHCP hosts. Removing the DHCP Server role from systems that do not actively require it eliminates the attack surface entirely, with the operational trade-off of requiring an alternative DHCP infrastructure.

Affected VersionsENISA

Windows Server 2025 (Server Core installation) 10.0.26100.0 <10.0.26100.33438
Windows Server 2012 R2 6.3.9600.0 <6.3.9600.23397
Windows Server 2016 10.0.14393.0 <10.0.14393.9512
Windows Server 2019 (Server Core installation) 10.0.17763.0 <10.0.17763.9245
Windows Server 2012 6.2.9200.0 <6.2.9200.26349
Windows Server 2012 R2 (Server Core installation) 6.3.9600.0 <6.3.9600.23397
Windows 10 Version 1809 10.0.17763.0 <10.0.17763.9245
Windows Server 2025 10.0.26100.0 <10.0.26100.33438
Windows Server 2016 (Server Core installation) 10.0.14393.0 <10.0.14393.9512
Windows Server 2019 10.0.17763.0 <10.0.17763.9245
Windows 10 Version 1607 10.0.14393.0 <10.0.14393.9512
Windows Server 2022 10.0.20348.0 <10.0.20348.5622
Windows Server 2012 (Server Core installation) 6.2.9200.0 <6.2.9200.26349

Affected Packages

euvd windows_10_version_1607 fix: 10.0.14393.9512
euvd windows_10_version_1809 fix: 10.0.17763.9245
euvd windows_server_2012 fix: 6.2.9200.26349
euvd windows_server_2012_r2 fix: 6.3.9600.23397
euvd windows_server_2012_r2_server_core_installation fix: 6.3.9600.23397
euvd windows_server_2012_server_core_installation fix: 6.2.9200.26349
euvd windows_server_2016 fix: 10.0.14393.9512
euvd windows_server_2016_server_core_installation fix: 10.0.14393.9512
euvd windows_server_2019 fix: 10.0.17763.9245
euvd windows_server_2019_server_core_installation fix: 10.0.17763.9245
euvd windows_server_2022 fix: 10.0.20348.5622
euvd windows_server_2025 fix: 10.0.26100.33438
euvd windows_server_2025_server_core_installation fix: 10.0.26100.33438

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

Windows DHCP Server is a built-in server role (typically hosted in dhcpssvc.dll) available on Windows Server editions. CWE-125 (Out-of-Bounds Read) describes a memory read operation that accesses memory outside the bounds of an allocated buffer. While OOB reads most directly enable information disclosure, their use to achieve code execution is well-established: a read beyond a buffer boundary can leak adjacent heap metadata, pointer values, or ASLR offsets that enable a follow-on write primitive. The 'Buffer Overflow' tag in the input metadata suggests a related write condition may also be present or is conflated with the OOB read. Affected versions span the full spectrum of Windows Server from 2012 (6.2.9200.0) through 2025 (10.0.26100.0), as well as Windows 10 versions 1607 and 1809, all of which support installation of the DHCP Server role. Fixed build boundaries are confirmed per EUVD data.

Know when Windows 10 1607 gets its next vulnerability

  • Watch products and get an email when something new is published
  • Check this CVE against your own stack and servers
  • Exploit and PoC references, threat intelligence from 22 sources

No credit card · 7-day full trial

Severity by source

Vendor (microsoft) PRIMARY 6.4 MEDIUM
AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H
vuln.today AI 6.4 MEDIUM

Local-only attack requiring existing admin-level access and high complexity; full impact triad warranted only if the memory corruption is successfully weaponized.

3.1 AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H
4.0 AV:L/AC:H/AT:P/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

Primary rating from Vendor (microsoft).

CVSS VectorVendor: microsoft

Attack Vector
Local
Attack Complexity
High
Privileges Required
High
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

Lifecycle Timeline

2
Patch available
Sep 08, 2026 - 18:35 EUVD
CVE Published
Sep 08, 2026 - 18:20 nvd
MEDIUM 6.4

DescriptionCVE.org

Out-of-bounds read in Windows DHCP Server allows an authorized attacker to execute code locally.

Threat Intelligence Overview

EPSS Score
0.2%
Top 88% exploitable
Prevalence
High
Windows Server DHCP role widely deployed across enterprise environments
Vendor Status
Publicly Disclosed:No
Exploited:No
Latest Software Release:Exploitation Less Likely
Data Quality
5 sources
Confidence: Medium

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.

SignalValue
Severity MEDIUM
CISA KEV No
Public POC No
EPSS 0.2%
Patch available Yes
Active threat No
Deciding rule
MEDIUM severity (CVSS 4.0-6.9)
What every action level means
Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.
Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.
This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.
This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.
Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision· derived
Defer
Exploitation
None
System Exposure· derived
Small
Automatable
No
Human Impact· derived
Medium
Technical Impact
Total

Priority Score

32
Low Medium High Critical
KEV: 0
EPSS: 0
CVSS: +32
PoC: 0
Weaponized: 0
Threat intel: 0
Gov advisory: 0

Attack Technique

A buffer overflow occurs when a program writes more data to a memory buffer than it was allocated to hold, causing the excess data to spill into adjacent memory regions.

CVE-2021-40444 HIGH POC
8.8 Sep 15

Windows MSHTML component contains a remote code execution vulnerability that allows attackers to craft malicious ActiveX

CVE-2021-34527 HIGH POC
8.8 Jul 02

<p>A remote code execution vulnerability exists when the Windows Print Spooler service improperly performs privileged fi

CVE-2022-30190 HIGH POC
7.8 Jun 01

Windows MSDT (Microsoft Support Diagnostic Tool) allows remote code execution when called via the ms-msdt URL protocol f

CVE-2017-0147 HIGH POC
7.5 Mar 17

The SMBv1 server in Microsoft Windows Vista SP2; Windows Server 2008 SP2 and R2 SP1; Windows 7 SP1; Windows 8.1; Windows

CVE-2018-8174 HIGH POC
7.5 May 09

The Windows VBScript engine contains a remote code execution vulnerability in object handling that allows full system co

CVE-2021-1675 HIGH POC
7.8 Jun 08

Windows Print Spooler Remote Code Execution Vulnerability. Rated high severity (CVSS 7.8), this vulnerability is no auth

CVE-2016-7255 HIGH POC
7.8 Nov 10

The Win32k kernel-mode driver in Windows Vista through Windows Server 2016 allows local privilege escalation, exploited

CVE-2023-36884 HIGH POC
7.5 Jul 11

Windows Search Remote Code Execution Vulnerability. Rated high severity (CVSS 7.5), this vulnerability is remotely explo

CVE-2023-44487 HIGH POC
7.5 Oct 10

Denial of service against HTTP/2 server implementations allows remote unauthenticated attackers to exhaust server resour

CVE-2024-30088 HIGH POC
7.0 Jun 11

Windows Kernel contains a TOCTOU race condition vulnerability allowing local privilege escalation, exploited by the OilR

CVE-2019-1458 HIGH POC
7.8 Dec 10

An elevation of privilege vulnerability exists in Windows when the Win32k component fails to properly handle objects in

CVE-2018-8453 HIGH POC
7.8 Oct 10

An elevation of privilege vulnerability exists in Windows when the Win32k component fails to properly handle objects in

This site uses cookies essential for authentication and security. No tracking or analytics cookies are used. Privacy Policy