CVE-2025-21351Network attack vector

Unauthenticated interruption of directory services

Published Feb 11, 2025 · Updated Feb 13, 2026

Denial of service in the Microsoft Windows Active Directory Domain Services API allows remote attackers to interrupt directory services over a network. Microsoft has not published the affected API operation, the malformed or excessive input it accepts, or whether exhaustion causes a hang or crash. No authentication or user interaction is required, and the documented consequence is limited to availability.

CVSS severity7.5
High
EPSS probability2.50%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in the Microsoft Windows Active Directory Domain Services API allows remote attackers to interrupt directory services over a network. Microsoft has not published the affected API operation, the malformed or excessive input it accepts, or whether exhaustion causes a hang or crash. No authentication or user interaction is required, and the documented consequence is limited to availability.

The record

CVE
CVE-2025-21351
Published
Feb 11, 2025
Updated
Feb 13, 2026
Vendor
Microsoft
Product
Windows Server 2019
Classifications
CWE-400, T1499
Attack vector
network
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

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=10.0.17763.0 <10.0.17763.6893

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Microsoft · Windows Server 2019version=10.0.17763.0 <10.0.17763.6893
Microsoft · Windows Server 2025 (Server Core installation)version=10.0.26100.0 <10.0.26100.3194
Microsoft · Windows Server 2016 (Server Core installation)version=10.0.14393.0 <10.0.14393.7785
Microsoft · Windows 11, version 24H2version=10.0.26100.0 <10.0.26100.3194
Microsoft · Windows 10 Version 21H2version=10.0.19044.0 <10.0.19044.5487
Microsoft · Windows Server 2022, 23H2 Edition (Server Core installation)version=10.0.25398.0 <10.0.25398.1425
Microsoft · Windows Server 2016version=10.0.14393.0 <10.0.14393.7785
Microsoft · Windows 11 Version 22H3version=10.0.22631.0 <10.0.22631.4890
Microsoft · Windows 10 Version 22H2version=10.0.19045.0 <10.0.19045.5487
Microsoft · Windows Server 2019 (Server Core installation)version=10.0.17763.0 <10.0.17763.6893
Microsoft · Windows 11 Version 23H2version=10.0.22631.0 <10.0.22631.4890
Microsoft · Windows 11, version 22H2version=10.0.22621.0 <10.0.22621.4890
Microsoft · Windows 10 Version 1607version=10.0.14393.0 <10.0.14393.7785
Microsoft · Windows Server 2022version=10.0.20348.0 <10.0.20348.3207
Microsoft · Windows Server 2025version=10.0.26100.0 <10.0.26100.3194
Microsoft · Windows 10 Version 1809version=10.0.17763.0 <10.0.17763.6893

Published CVSS scores

7.5Microsoft CorporationCVSS:3.1/AV:N/AC:L/PR:N/UI:N/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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

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

Weakness, pattern, technique

CWE-400Uncontrolled Resource Consumption
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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