Windows
CVE-2026-21243
HIGH
Severity by source
AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Primary rating from NVD · only source for this CVE.
CVSS VectorNVD
Lifecycle Timeline
2DescriptionCVE.org
Null pointer dereference in Windows LDAP - Lightweight Directory Access Protocol allows an unauthorized attacker to deny service over a network.
AnalysisAI
Windows LDAP service in Server 2022 and 2022 23H2 is vulnerable to denial of service through a null pointer dereference that can be triggered remotely without authentication. An attacker can exploit this flaw over the network to crash the LDAP service and disrupt directory access functionality. No patch is currently available for this vulnerability.
Technical ContextAI
Classified as CWE-476 (NULL Pointer Dereference). Affects Windows Server 2019. Null pointer dereference in Windows LDAP - Lightweight Directory Access Protocol allows an unauthorized attacker to deny service over a network.
RemediationAI
Monitor vendor advisories for a patch. Restrict network access to the affected service where possible.
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Same weakness CWE-476 – NULL Pointer Dereference
View allSame technique Null Pointer Dereference
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External POC / Exploit Code
Leaving vuln.today