Chaotic Eclipse has unveiled a proof-of-concept (PoC) for a Windows privilege escalation zero-day vulnerability, codenamed MiniPlasma, which targets the "cldflt.sys" component and could grant SYSTEM privileges on fully patched Windows systems. This vulnerability was initially reported to Microsoft by James Forshaw from Google Project Zero in September 2020. Although Microsoft was believed to have resolved it in December 2020 as part of CVE-2020-17103, further analysis indicates that the flaw remains unaddressed. Chaotic Eclipse demonstrated that the original PoC could still spawn a SYSTEM shell reliably on his machines. The vulnerability is believed to affect all versions of Windows, with confirmation that MiniPlasma opens a "cmd.exe" prompt with SYSTEM privileges on Windows 11 systems with the latest May 2026 updates, though it does not function on the latest Insider Preview Canary version. In December 2025, Microsoft addressed a separate privilege escalation flaw in the same component, identified as CVE-2025-62221, which had a CVSS score of 7.8 and was reportedly being exploited by threat actors.