CVE-2026-78503 Advisory
Severity: Medium (CVSS 6.5)
KEV Status: Not exploited in the wild
Affected Product:
- Microsoft Defender Business
Vulnerability: Out-of-bounds read in Microsoft Office Word allows unauthorized information disclosure over a network.
Remediation: Apply security updates via Microsoft Security Response Center (MSRC): https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-78503
Action Required: Review and deploy available patches to affected systems.