ACTIVELY EXPLOITED

CVE-2021-34484: Microsoft Windows User Profile Service Privilege Escalation Vulnerability

Facts
VendorMicrosoft
ProductWindows
Actively exploitedYes
Added to CISA KEV31 Mar 2022
CISA federal deadline21 Apr 2022
Weakness (CWE)CWE-269

Required action (CISA's text)

Apply updates per vendor instructions.

Description (NVD)

Microsoft Windows User Profile Service contains an unspecified vulnerability that allows for privilege escalation.

SOURCES

Other Microsoft flaws

Data from NVD, CISA KEV, FIRST EPSS and vendor advisories. Updated 10 Nov 2026.