A proof-of-concept exploit for a Microsoft Defender zero-day vulnerability, known as "RedSun," has been released by a researcher, granting SYSTEM privileges to attackers. This is the second zero-day exploit published in two weeks, with the researcher expressing dissatisfaction with Microsoft's collaboration with cybersecurity researchers. The "RedSun" exploit allows attackers to escalate privileges, posing a significant threat to systems running Microsoft Defender. The vulnerability can be exploited to gain elevated access, enabling malicious activities such as data theft and system compromise. As zero-day activity targeting Microsoft increases, the window for patching vulnerabilities is rapidly shrinking1. This development underscores the need for immediate assessment of exposure to mitigate potential risks. The release of this exploit highlights the ongoing challenges in the relationship between vendors and researchers, with significant implications for system security. So what matters to practitioners is that they must swiftly evaluate their systems' vulnerability to this exploit to prevent potential breaches.