Researcher Drops New Windows Zero-Day PoC Hours After Microsoft Patch Tuesday

**Executive summary:** Security researcher 'Chaotic Eclipse' published a proof-of-concept named LegacyHive that allows non‑admin users to mount and modify other users' registry hives (a powerful local privilege escalation primitive) reportedly effective across supported Windows releases; Microsoft is investigating, while the update cycle also addressed multiple actively exploited SharePoint Server vulnerabilities added to CISA's Known Exploited Vulnerabilities list.