EUVD-2026-29598
GHSA-7rv3-r8mg-4wcp
Severity by source
AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Local-only attack requiring a low-privileged account to trigger LDAP null pointer dereference; no confidentiality or integrity impact, availability fully lost on crash.
Primary rating from NVD.
CVSS VectorNVD
Lifecycle Timeline
2DescriptionCVE.org
Null pointer dereference in Windows LDAP - Lightweight Directory Access Protocol allows an authorized attacker to deny service locally.
AnalysisAI
Null pointer dereference in the Windows LDAP (Lightweight Directory Access Protocol) component enables a low-privileged local attacker to crash the LDAP service, causing a denial of service on all affected Windows 10, Windows 11, and Windows Server releases. The vulnerability carries a CVSS 3.1 score of 5.5 with a strictly local attack vector (AV:L/PR:L), confining impact to availability only - no data exfiltration or code execution is possible. With EPSS at 0.04% (11th percentile), SSVC exploitation status of 'none,' no KEV listing, and no public exploit identified, real-world exploitation risk is currently low despite the enormous Windows install base.
Technical ContextAI
CWE-476 (Null Pointer Dereference) describes a code path that attempts to dereference a pointer that is null or uninitialized, producing an unhandled exception that terminates the affected process. The flaw resides in the Windows LDAP client library, a core OS component used for querying and modifying directory services - most critically Active Directory in enterprise environments. CPE data confirms the affected scope spans Microsoft Windows 10 versions 1607, 1809, 21H2, and 22H2; Windows 11 versions 22H3, 23H2, 24H2, 25H2, and 26H1; and Windows Server 2016, 2019, 2022 (including 23H2 Server Core edition), and 2025. Because LDAP client functionality ships enabled by default across all these SKUs, no non-default configuration is required to expose the vulnerable code path.
RemediationAI
Apply the Microsoft-released patch documented in the MSRC advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-34339 via Windows Update or WSUS. Fixed builds per EUVD version data are: Windows 11 24H2 → 10.0.26100.8457 or later; Windows 11 25H2 → 10.0.26200.8457 or later; Windows 11 26H1 → 10.0.28000.2113 or later; Windows 11 23H2/22H3 → 10.0.22631.7079 or later; Windows 10 22H2 → 10.0.19045.7291 or later; Windows 10 21H2 → 10.0.19044.7291 or later; Windows 10 1809/Server 2019 → 10.0.17763.8755 or later; Windows 10 1607/Server 2016 → 10.0.14393.9140 or later; Windows Server 2022 → 10.0.20348.5139 or later; Server 2022 23H2 Core → 10.0.25398.2330 or later; Server 2025 → 10.0.26100.32860 or later. If immediate patching cannot be completed, restrict interactive and remote desktop logon rights to only operationally necessary accounts on LDAP-dependent systems - this raises the effective privilege bar for exploitation but does not eliminate it. Note that restricting local logon broadly may impact helpdesk and administrative workflows. Given the local-only, DoS-only nature of this vulnerability, deferral to the next scheduled patch cycle is defensible for most environments.
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Same weakness CWE-476 – NULL Pointer Dereference
View allSame technique Denial Of Service
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External POC / Exploit Code
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