CVE-2025-21335

What is affected

Vendor	Microsoft
Product	Windows
Weakness	CWE-416

The vulnerability

Microsoft Windows Hyper-V NT Kernel Integration VSP contains a use-after-free vulnerability that allows a local attacker to gain SYSTEM privileges.

Required action

Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

US federal civilian agencies were required to act by 4 February 2025 under BOD 22-01. The deadline is a compliance date, not a measure of severity — it says nothing about how dangerous the flaw is to anyone else.

Where this comes from

Every field on this page is taken from the CISA Known Exploited Vulnerabilities catalog, last synced 12 Nov 2026, 00:29. Nothing here is our own assessment. For the technical scoring, see the NVD record below.

NVD record ↗ CVE.org record ↗