Heap-based buffer overflow in Microsoft Office - CVE-2026-111301

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 processing specially crafted database files. A remote attacker can convince a user to open a crafted database in Access and edit a record in a linked table to execute arbitrary code with that user's permissions.

The Preview Pane is not an attack vector.

Affected software

How to mitigate CVE-2026-111301

External References

• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2026-111301
• https://learn.microsoft.com/en-us/officeupdates/microsoft365-apps-security-updates

Related Security Bulletins

• Multiple vulnerabilities in Microsoft Office