A bad security intelligence update causes Microsoft Defender to crash during Full and Quick Scans on some PCs. Upgrading to Security Intelligence Update v1.457.236.0 resolves the issue.

Microsoft has resolved a known issue that causes incorrect alerts warning that Defender Antivirus was turned off after installing recent updates.

After installing the latest Defender Antivirus update for Windows 11, users have started reporting that their operating ...

Microsoft has resolved a bug that caused Windows Defender to crash after a recent security update, resulting in 0xc0000005 access violation errors on some affected systems.

Microsoft has released a new Microsoft Defender update package for Windows installation images, refreshing the security protection included with Windows setup media following the August 2026 Patch ...

A researcher released ShieldCrash on September 8, claiming it bypasses Microsoft's Defender fix for flaw CVE-2026-69414.

Microsoft fixed a Defender false positive that flagged legitimate DigiCert certificates as malware, disrupting Windows trust stores for some IT teams. A Microsoft Defender update turned trusted ...

A week ago, the security researcher who goes by “Nightmare Eclipse” published information about RoguePlanet, a zero-day security vulnerability in Microsoft’s Defender security program. The ...

The majority of the updates that come through Windows Update are for Windows Defender, and for good reason. Windows Defender helps make your antimalware and other security protections stronger.

See how Microsoft Defender detects and disrupts AI-themed phishing, malware, and multi-stage attacks across the attack chain.