Heap-based buffer overflow in Microsoft products - CVE-2026-69778

Vulnerability details

The vulnerability allows a remote attacker to execute arbitrary code.

The vulnerability exists due to a heap-based buffer overflow in Microsoft Access when opening a specially crafted file. A remote attacker can trick the victim into opening a specially crafted file to execute arbitrary code.

The Preview Pane is not an attack vector.

Affected software

How to mitigate CVE-2026-69778

External References

• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2026-69778
• https://docs.microsoft.com/en-us/officeupdates/microsoft365-apps-security-updates

Related Security Bulletins

• Multiple vulnerabilities in Microsoft Office