CVE-2026-78511 Security Advisory
Severity: HIGH (CVSS 8.8)
Affected Product:
- Microsoft Defender Business
Vulnerability Description: Heap-based buffer overflow in Microsoft Office Word enables remote code execution via network attack vector.
KEV Status: Not currently listed as exploited in the wild
Remediation: Apply security updates from Microsoft Security Response Center at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-78511
Recommendation: Prioritize patching due to high CVSS score and remote exploitability. Deploy updates as soon as available through standard patch management processes.