Windows Update Medic Service Elevation of Privilege Vulnerability

Summary

The Windows Update Medic Service, a built-in component of Microsoft Windows, contains a flaw that could allow a local user with limited access to gain higher, system-level privileges. An attacker who can already run code on the affected machine could use this to take full control of the system.

Summarized by anthropic/claude-haiku-5.5. Verify details against the original sources.

Timeline

1. Aug 12, 2021, 6:12 PM UTCCVE published
2. Nov 3, 2021Added to CISA KEV

   CISA has evidence of exploitation in the wild

3. Nov 17, 2021CISA remediation deadline

   Due date for US federal agencies to patch

4. Aug 10, 2026, 3:10 PM UTCRecord last updated
5. Oct 22, 2026EPSS reached 10%

   FIRST estimates at least a 10% chance of exploitation in the next 30 days

Affected versions

• Microsoft Windows 10 Version 1809

  From 10.0.17763.0 · fixed in 10.0.17763.2114

• Microsoft Windows 10 Version 1809

  From 10.0.0 · fixed in 10.0.17763.2114

• Microsoft Windows 10 Version 1909

  From 10.0.0 · fixed in 10.0.18363.1734

• Microsoft Windows 10 Version 2004

  From 10.0.0 · fixed in 10.0.19041.1165

• Microsoft Windows 10 Version 20H2

  From 10.0.0 · fixed in 10.0.19042.1165

• Microsoft Windows 10 Version 21H1

  From 10.0.0 · fixed in 10.0.19043.1165

• Microsoft Windows Server 2019

  From 10.0.17763.0 · fixed in 10.0.17763.2114

• Microsoft Windows Server 2019 (Server Core installation)

  From 10.0.17763.0 · fixed in 10.0.17763.2114

• Microsoft Windows Server version 2004

  From 10.0.0 · fixed in 10.0.19041.1165

• Microsoft Windows Server version 20H2

  From 10.0.0 · fixed in 10.0.19042.1165

References 1