- Microsoft released 56 security updates for Patch Tuesday in December 2025, including a zero-day bug and multiple privilege escalation vulnerabilities. - The most critical bugs involve Microsoft Office and Outlook, with the potential to be exploited via email messages viewed in the Preview Pane. - Privilege escalation flaws are considered more likely to be exploited, particularly CVE-2025-62458, CVE-2025-62470, CVE-2025-62472, CVE-2025-59516, and CVE-2025-59517.