Heap-based buffer overflow in Microsoft Office - CVE-2026-109493

Vulnerability details

The vulnerability allows a remote attacker to execute arbitrary code with the victim user's permissions.

The vulnerability exists due to a heap-based buffer overflow in Microsoft Office Access when handling database objects dragged to another application. A remote attacker can provide a specially crafted database and convince a user to open it in Microsoft Access and drag an object from it to another application to execute arbitrary code with the user's permissions.

Affected software

How to mitigate CVE-2026-109493

External References

• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2026-109493
• https://learn.microsoft.com/en-us/officeupdates/microsoft365-apps-security-updates

Related Security Bulletins

• Multiple vulnerabilities in Microsoft Office