Microsoft has fixed a known issue that caused Windows Security to wrongly report that Microsoft Defender Antivirus was turned off after recent updates. The bug affected supported Windows client and server versions, including Windows 11 26H1 and Windows Server 2025, and was resolved in Defender Antivirus update version 4.18.26080.4 released on September 17. #MicrosoftDefenderAntivirus #WindowsSecurity #Windows11 #WindowsServer2025
Keypoints
- Microsoft fixed false alerts claiming Defender Antivirus was turned off.
- The issue was resolved in version 4.18.26080.4 on September 17.
- The bug affected supported Windows client and server releases.
- Windows Security could repeatedly prompt users to turn Defender back on.
- Microsoft has faced several similar incorrect update-related alerts this year.