Unpatched Microsoft Defender Flaw Lets Hackers Gain Admin Access on Windows

An unpatched vulnerability in (ironically) Microsoft Defender lets attackers gain full administrative access on Windows 10 and 11, and on some Windows Server versions, once they already have local access to a machine.

A security researcher who goes by the name Chaotic Eclipse discovered what they call the “RedSun” vulnerability just weeks after discovering, disclosing, and then leaking a Windows zero-day exploit that Microsoft failed to properly address the issue. This new flaw works as a local privilege escalation issue. An attacker must first gain a foothold on a target device, such as through a phishing email or a malicious program, and then use the Defender exploit to escalate from a standard account to admin or even SYSTEM, as reported by PCWorld.

This allows hackers to exploit how Defender handles high‑privilege tasks, uses file-system tricks, and manipulates registry data to reset and then restore administrator credentials. The process can make it harder for…