Patch Tuesday Zero-Day Lessons: What February 2024's Two Exploited Flaws Still Teach Us [2026]

Patch Tuesday Zero-Day Lessons: What February 2024's Two Exploited Flaws Still Teach Us On February 13, 2024, Microsoft's Patch Tuesday dropped fixes for 73 vulnerabilities. Two of them — CVE-2024-21412 and CVE-2024-21338 — were already being exploited in the wild before the patches arrived. One let attackers bypass Windows' most visible security warning. The other gave them kernel-level SYSTEM privileges. Chain them together and you get an attack path that's brutally effective and, honestly, completely preventable. Two years later, the Patch Tuesday zero-day playbook hasn't changed much. If anything, February 2024's patterns have become more relevant, not less. I've spent fourteen-plus years building and securing production systems, and these two CVEs are the ones I keep pulling up when I'm talking to teams about why patching cadence actually matters. They're a near-perfect case study in how attackers think. And they expose something uncomfortable: the gap between "patch available" an