CVE-2026-70220 Microsoft Office Word Remote Code Execution Vulnerability

High 7.8 Published Updated

Heap-based buffer overflow in Microsoft Office Word allows local attackers to execute arbitrary code.

Exploited in the wild
Not known
Login needed
Not needed
Attackable
Local or same network only
Victim action needed
A user has to click or open something
Fix
None listed

What is CVE-2026-70220?

CVE-2026-70220 is a high-severity memory corruption vulnerability in Microsoft 365 Apps, published on 13 Oct 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

Official description

Heap-based buffer overflow in Microsoft Office Word allows an unauthorized attacker to execute code locally.

Weakness: CWE-122

Which versions are affected by CVE-2026-70220?

It affects 4 products.

Products include Microsoft 365 Apps, Microsoft Microsoft 365, Microsoft Office 2021, Microsoft Office 2024.

How do I fix CVE-2026-70220?

No fix has been published for CVE-2026-70220 yet. Limit exposure of the affected software until one is available.

Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.

Is CVE-2026-70220 being exploited?

There is no known exploitation of CVE-2026-70220 in the wild and no public exploit code.

All Microsoft 365 Apps vulnerabilities

Sources

Also known as GHSA-jj63-2mwj-35pw.

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