CVE-2026-88091 Windows Management Instrumentation Elevation of Privilege Vulnerability

High 7.8 Published Updated

An authorized local attacker can elevate privileges via deserialization of untrusted data in Windows Management Instrumentation.

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-2026-88091?

CVE-2026-88091 is a high-severity unsafe deserialization vulnerability in Microsoft Windows 10 1607, published on 13 Oct 2026. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

Deserialization of untrusted data in Windows Management Instrumentation allows an authorized attacker to elevate privileges locally.

Weakness: CWE-502

Which versions are affected by CVE-2026-88091?

It affects 14 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 8 more.

How do I fix CVE-2026-88091?

No fix has been published for CVE-2026-88091 yet. Limit exposure of the affected software until one is available.

Upgrade, and only deserialise data from trusted sources or with an allow-list of types. More about Unsafe deserialization.

Is CVE-2026-88091 being exploited?

There is no known exploitation of CVE-2026-88091 in the wild and no public exploit code.

All Microsoft Windows 10 1607 vulnerabilities

Sources

Also known as GHSA-gp73-qfv5-gmpw.

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