Microsoft Defender 0-Day Vulnerability Enables Privilege Escalation Attack

**Executive Summary:** Microsoft disclosed CVE-2026-33825, an Important (CVSS 3.1 base score 7.8) elevation-of-privilege zero-day in the Defender Antimalware Platform that allows a local, low-privileged user to obtain SYSTEM privileges; Microsoft has released a patch (platform version 4.18.26030.3011) and recommends verifying updates, noting no observed in-the-wild exploitation but assessing exploitation as "More Likely".