Stack-based buffer overflow in Microsoft Office for macOS and Microsoft Office - CVE-2026-108440

Vulnerability details

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

The vulnerability exists due to a stack-based buffer overflow in Microsoft Office Word when processing a malicious RTF file. A remote attacker can craft an RTF file and induce a user to open it or render it in the preview pane to execute arbitrary code in the user's context.

Affected software

How to mitigate CVE-2026-108440

External References

• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2026-108440
• https://learn.microsoft.com/en-us/officeupdates/release-notes-office-for-mac

Related Security Bulletins

• Multiple vulnerabilities in Microsoft Office