CVE-2026-21243

HighCVSS 7.5/10Last modified Jun 17, 2026

Description

Null pointer dereference in Windows LDAP - Lightweight Directory Access Protocol allows an unauthorized attacker to deny service over a network.

Metrics

CVSS 3.1 7.5/10CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Weakness enumeration

Affected software

VendorProductVersions
MicrosoftWindows Server 2019>= 10.0.17763.0, < 10.0.17763.8389
MicrosoftWindows Server 2019 (Server Core installation)>= 10.0.17763.0, < 10.0.17763.8389
MicrosoftWindows Server 2022>= 10.0.20348.0, < 10.0.20348.4773
MicrosoftWindows Server 2022, 23H2 Edition (Server Core installation)>= 10.0.25398.0, < 10.0.25398.2149
MicrosoftWindows Server 2025>= 10.0.26100.0, < 10.0.26100.32370
MicrosoftWindows Server 2025 (Server Core installation)>= 10.0.26100.0, < 10.0.26100.32370

References

Timeline

Published
Feb 10, 2026
Last modified
Jun 17, 2026
NVD status
Analyzed

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CVE-2026-21243: High severity, CVSS 7.5 | Vulnix