January 2026 CVE Landscape: 23 Critical Vulnerabilities Mark 5% Increase, APT28 Exploits Microsoft Office Zero-Day

**Recorded Future Insikt Group: January 2026 — High-impact active exploitation across enterprise software**: The report details 23 vulnerabilities exploited in the wild during January 2026, highlights APT28's zero-day campaign (CVE-2026-21509) that delivered email-collection and backdoor implants, documents widespread authentication-bypass and pre-authentication RCE flaws (SmarterMail, Ivanti, Modular DS, Cisco, etc.), lists IoCs and Nuclei templates, and provides immediate remediation and detection guidance.