Heap-based buffer overflow in Microsoft Office LTSC and Microsoft Office for Android - CVE-2026-42831

Vulnerability details

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to a boundary error in Microsoft Office. A remote attacker can trick a victim to open a specially crafted Office file, trigger a heap-based buffer overflow and execute arbitrary code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

Affected software

How to mitigate CVE-2026-42831

External References

• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-42831

Related Security Bulletins

• Multiple vulnerabilities in Microsoft Office