A previously patched elevation-of-privilege vulnerability in the Windows Cloud Filter driver "cldflt.sys" has resurfaced, allowing attackers to gain SYSTEM-level privileges. The flaw, initially reported by Google Project Zero researcher James Forshaw in 2020, was recently reexploited by researcher Nightmare Eclipse, raising questions about the effectiveness of Microsoft's original patch. The vulnerability's resurgence has significant implications for Windows security, as it potentially enables malicious actors to escalate privileges and gain unrestricted access to system resources. The fact that this flaw remains exploitable six years after its initial disclosure suggests that Microsoft's patch may have been incomplete or inadequate1. This matters to security practitioners because it highlights the importance of thorough vulnerability remediation and the need for continuous monitoring of supposedly patched flaws to prevent their reemergence as zero-day exploits.