All news & advisories
High

CVE-2026-78504: Security Advisory

CVE-2026-78504 CVSS 8.8
Who it affects
See the summary below.
What to do
Apply the vendor's update in your next patch window.

CVE-2026-78504 Advisory

Severity: HIGH (CVSS 8.8)

Affected Product:

  • Microsoft Defender Business

Vulnerability: Stack-based buffer overflow in Microsoft Office Word enabling remote code execution.

KEV Status: Not currently exploited in the wild

Remediation: Apply security updates from Microsoft. Refer to the Microsoft Security Response Center advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-78504

Action: Prioritize patching given the network-exploitable nature and high CVSS score.

Data as of September 9, 2026. Sources: nvd.nist.gov, msrc.microsoft.com. Figures are pulled from public vendor and security data and refreshed automatically.
Back to all news & advisories