CVE-2025-21179

Service interruption via out-of-bounds DHCP read

Published Feb 11, 2025 · Updated Feb 13, 2026

Out-of-bounds read in Microsoft Windows DHCP Client Service before build 10.0.26100.3194 allows attackers to interrupt service. Microsoft has not disclosed which DHCP message field is read beyond its buffer or the code path that performs the invalid read. Exploitation requires adjacent network access and user interaction; the reported impact is limited to availability.

CVSS severity4.8
Medium
EPSS probability0.75%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds read in Microsoft Windows DHCP Client Service before build 10.0.26100.3194 allows attackers to interrupt service. Microsoft has not disclosed which DHCP message field is read beyond its buffer or the code path that performs the invalid read. Exploitation requires adjacent network access and user interaction; the reported impact is limited to availability.

The record

CVE
CVE-2025-21179
Published
Feb 11, 2025
Updated
Feb 13, 2026
Vendor
Microsoft
Product
Windows Server 2025 (Server Core installation)
Classifications
CWE-125, T1499
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 11, 2025CVE publishedPublication date reported by the CVE source.
  2. Feb 13, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=10.0.26100.0 <10.0.26100.3194

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

Microsoft · Windows Server 2025 (Server Core installation)version=10.0.26100.0 <10.0.26100.3194
Microsoft · Windows 11, version 24H2version=10.0.26100.0 <10.0.26100.3194
Microsoft · Windows Server 2025version=10.0.26100.0 <10.0.26100.3194

Published CVSS scores

4.8MicrosoftCVSS:3.1/AV:A/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-125Out-of-bounds Read
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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