Microsoft fixes bug behind ‘Defender Antivirus is turned off’ alerts
Microsoft's Defender Antivirus update 4.18.26080.4 fixes false 'Defender Antivirus is turned off' alerts affecting all supported Windows client and server versions.
Microsoft confirmed in a Windows release health dashboard update that a known issue causing erroneous 'Microsoft Defender Antivirus is turned off' notifications is fixed in the Defender Antivirus update (version 4.18.26080.4) released September 17. The bug affected all supported Windows client and server versions, including Windows 11 26H1 and Windows Server 2025, and triggered alerts even when the antivirus was active and notification settings were disabled. Microsoft had acknowledged the issue in late August after it appeared in the Windows Insider Release Preview channel since at least June.
- Fix shipped in Microsoft Defender Antivirus update 4.18.26080.4 released September 17
- Bug affected all supported Windows clients and servers, including Windows 11 26H1 and Windows Server 2025
- Erroneous alerts appeared at startup and intermittently, even with notification settings turned off
- Vendors
- Microsoft
From the original article
2 min read at bleepingcomputer.com
Microsoft has resolved a known issue that causes incorrect alerts warning that Defender Antivirus was turned off after installing recent updates. [...]
By Sergiu Gatlan · bleepingcomputer.com
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