CVE-2026-55045 Microsoft Office Remote Code Execution Vulnerability

High 8.4 Published Updated

An out-of-bounds read in Microsoft Office allows local attackers to execute arbitrary code, requiring users to apply vendor patches.

Exploited in the wild
Not known
Login needed
Not needed
Attackable
Local or same network only
Victim action needed
Not needed
Fix
None listed

What is CVE-2026-55045?

CVE-2026-55045 is a high-severity memory corruption vulnerability in Microsoft 365 Apps, published on 14 Jul 2026. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

Out-of-bounds read in Microsoft Office allows an unauthorized attacker to execute code locally.

Weakness: CWE-125

Which versions are affected by CVE-2026-55045?

It affects 7 products.

Products include Microsoft 365 Apps, Microsoft Microsoft 365, Microsoft Office 2016, Microsoft Office 2019, Microsoft Office 2021, Microsoft Office 2024 and 1 more.

How do I fix CVE-2026-55045?

No fix has been published for CVE-2026-55045 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-2026-55045 being exploited?

There is no known exploitation of CVE-2026-55045 in the wild and no public exploit code.

All Microsoft 365 Apps vulnerabilities

Sources

Also known as GHSA-65x2-ccc4-wp24.

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