# CVE-2026-21509

> Reliance on untrusted inputs in a security decision in Microsoft Office allows an unauthorized attacker to bypass a security feature locally.

- **CVSS:** 7.8 (HIGH)
- **EPSS:** 7.5%
- **CISA KEV:** yes
- **CWE:** CWE-807

Canonical: https://intel.threadlinqs.com/cve/CVE-2026-21509
Full threat coverage + IOCs via the Threadlinqs MCP server (Purple tier): https://intel.threadlinqs.com/mcp