Heap-based buffer overflow in Microsoft Office for macOS and Microsoft Office - CVE-2026-108444

Vulnerability details

The vulnerability allows a remote attacker to execute arbitrary code in the user's context.

The vulnerability exists due to a heap-based buffer overflow in Microsoft Office when processing a specially crafted file opened in Microsoft Excel and saved as a web page. A remote attacker can send a specially crafted file and convince a user to open it in Excel and save it as a web page to execute arbitrary code in the user's context.

Affected software

How to mitigate CVE-2026-108444

External References

• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2026-108444
• https://learn.microsoft.com/en-us/officeupdates/microsoft365-apps-security-updates

Related Security Bulletins

• Multiple vulnerabilities in Microsoft Office