CVE-2026-21243
Analyzed Analyzed - Analysis Complete
Null Pointer Dereference in Windows LDAP Causes DoS Attack

Publication date: 2026-02-10

Last updated on: 2026-02-11

Assigner: Microsoft Corporation

Description
Null pointer dereference in Windows LDAP - Lightweight Directory Access Protocol allows an unauthorized attacker to deny service over a network.
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Meta Information
Published
2026-02-10
Last Modified
2026-02-11
Generated
2026-06-16
AI Q&A
2026-02-10
EPSS Evaluated
2026-06-15
NVD
CVE-2026-21243
EUVD
EUVD-2026-7317
Affected Vendors & Products
Showing 4 associated CPEs
Vendor Product Version / Range
microsoft windows_server_2019 to 10.0.17763.8389 (exc)
microsoft windows_server_2022 to 10.0.20348.4711 (exc)
microsoft windows_server_2025 to 10.0.26100.32313 (exc)
microsoft windows_server_2022_23h2 to 10.0.25398.2149 (exc)
Helpful Resources
Exploitability
CWE
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KEV
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CWE ID Description
CWE-476 The product dereferences a pointer that it expects to be valid but is NULL.
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Executive Summary

This vulnerability is a null pointer dereference in the Windows LDAP (Lightweight Directory Access Protocol) component.

It allows an unauthorized attacker to cause a denial of service over a network by exploiting this flaw.

Impact Analysis

The vulnerability can be exploited by an unauthorized attacker to cause a denial of service (DoS) condition.

This means that affected Windows LDAP services could become unavailable, disrupting network operations that rely on LDAP.

Compliance Impact

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Detection Guidance

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