CVE-2026-78521
Severity: HIGH (CVSS 8.8)
Description: Heap-based buffer overflow in Microsoft Office Word allows remote code execution.
Affected Product:
- Microsoft Defender Business
KEV Status: Not listed as actively exploited
Remediation:
- Apply security updates from Microsoft Security Response Center
- Reference: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-78521
Recommendation: Prioritize patching due to HIGH severity and remote exploitation vector.