Heap-based buffer overflow in Microsoft Office for macOS and Microsoft Office - CVE-2026-111294

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 Word when processing embedded shapes in specially crafted documents. A remote attacker can provide a specially crafted Word document and convince a user to open it for editing and use Edit Points on an embedded shape to execute arbitrary code with that user's permissions.

The Preview Pane is not an attack vector for this vulnerability.

Affected software

How to mitigate CVE-2026-111294

External References

• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2026-111294
• https://docs.microsoft.com/en-us/officeupdates/microsoft365-apps-security-updates

Related Security Bulletins

• Multiple vulnerabilities in Microsoft Office