Heap-based buffer overflow in Microsoft Office for macOS and Microsoft Office - CVE-2026-116718

Vulnerability details

The vulnerability allows a remote attacker to execute arbitrary code.

The vulnerability exists due to a heap-based buffer overflow in Microsoft Office Word when processing a specially crafted Office document. A remote attacker can send a malicious Office file to a user and convince them to open it to execute arbitrary code.

Successful exploitation requires the application to be able to allocate a large amount of memory while processing the crafted document.

Affected software

How to mitigate CVE-2026-116718

External References

• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2026-116718
• https://learn.microsoft.com/en-us/officeupdates/release-notes-office-for-mac

Related Security Bulletins

• Multiple vulnerabilities in Microsoft Office