CVE-2025-59257 Windows Local Session Manager (LSM) Denial of Service Vulnerability

Medium 6.5 Published Updated

An authorized attacker can cause a denial of service in Windows Local Session Manager by exploiting improper input validation over the network.

Exploited in the wild
Not known
Login needed
Any signed-in user
Attackable
Over the internet
Victim action needed
Not needed
Fix
None listed

What is CVE-2025-59257?

CVE-2025-59257 is a medium-severity denial of service vulnerability in Microsoft Windows 11 24h2, published on 14 Oct 2025. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

Improper validation of specified type of input in Windows Local Session Manager (LSM) allows an authorized attacker to deny service over a network.

Weakness: CWE-1287

Which versions are affected by CVE-2025-59257?

It affects 4 products.

Products include Microsoft Windows 11 24h2, Microsoft Windows 11 25h2, Microsoft Windows Server 2022 23h2, Microsoft Windows Server 2025.

How do I fix CVE-2025-59257?

No fix has been published for CVE-2025-59257 yet. Limit exposure of the affected software until one is available.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2025-59257 being exploited?

There is no known exploitation of CVE-2025-59257 in the wild and no public exploit code.

All Microsoft Windows 11 24h2 vulnerabilities

Sources

Also known as GHSA-37x9-hxcw-w9fv.

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