CVE-2026-58598: Microsoft Windows 10 21h2

High severity, CVSS 7.0. EPSS: 0.2% chance of exploitation in the next 30 days.

Concurrent execution using shared resource with improper synchronization ('race condition') in Windows Backup Engine allows an authorized attacker to elevate privileges locally.

Affected products

• Microsoft Windows 10 21h2: before 10.0.19044.7548 (fixed in 10.0.19044.7548)
• Microsoft Windows 10 22h2: before 10.0.19045.7548 (fixed in 10.0.19045.7548)
• Microsoft Windows 11 24h2: before 10.0.26100.8875 (fixed in 10.0.26100.8875)
• Microsoft Windows 11 25h2: before 10.0.26200.8875 (fixed in 10.0.26200.8875)
• Microsoft Windows 11 26h1: before 10.0.28000.2525 (fixed in 10.0.28000.2525)

Published 2026-07-16. Last modified 2026-07-22.