Windows 10 ESU and LTSC 2021: Security Update im Detail

What changed

KB5120249 is the August cumulative security update for Windows 10 ESU 22H2 and Enterprise or IoT Enterprise LTSC 2021 21H2.

Technical details

• Security: August security fixes
• Backup: fixes File History backups to SMB shares failing with an invalid-credentials error
• Secure Boot: expands high-confidence targeting for renewed certificates
• Servicing stack: KB5104021 to build 19041.7546

Why it matters

Windows 10 ESU and LTSC remain separate servicing populations with distinct build targets and entitlement requirements.

Known limitations

• Microsoft currently reports no known issue
• Windows 10 22H2 requires ESU entitlement
• The latest servicing stack is required before the update is offered

Now check

• Separate ESU 22H2 and LTSC 2021 inventory
• Deploy KB5120249 to pilot rings
• Report builds 19045.7663 and 19044.7663 and verify ESU activation