CVE-2026-34339 Windows Lightweight Directory Access Protocol (LDAP) Denial of Service Vulnerability

Medium 5.5 Published Updated

An authorized local attacker can cause a denial of service in Windows LDAP via a null pointer dereference.

Exploited in the wild
Not known
Login needed
Any signed-in user
Attackable
Local or same network only
Victim action needed
Not needed
Fix
None listed

What is CVE-2026-34339?

CVE-2026-34339 is a medium-severity vulnerability in Microsoft Windows 10 1607, published on 12 May 2026. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

Null pointer dereference in Windows LDAP - Lightweight Directory Access Protocol allows an authorized attacker to deny service locally.

Weakness: CWE-476

Which versions are affected by CVE-2026-34339?

It affects 13 products.

Products include Microsoft Windows 10 1607, Microsoft Windows 10 1809, Microsoft Windows 10 21h2, Microsoft Windows 10 22h2, Microsoft Windows 11 23h2, Microsoft Windows 11 24h2 and 7 more.

How do I fix CVE-2026-34339?

No fix has been published for CVE-2026-34339 yet. Limit exposure of the affected software until one is available.

Is CVE-2026-34339 being exploited?

There is no known exploitation of CVE-2026-34339 in the wild and no public exploit code.

All Microsoft Windows 10 1607 vulnerabilities

Sources

Also known as GHSA-7rv3-r8mg-4wcp.

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