CVE-2026-62913 Microsoft Exchange Server Remote Code Execution Vulnerability

High 8.8 Published Updated

An authorized attacker can execute arbitrary code on Microsoft Exchange Server via a heap-based buffer overflow.

Exploited in the wild
Not known
Login needed
Any signed-in user
Attackable
Over the internet
Victim action needed
Not needed
Fix
None listed

What is CVE-2026-62913?

CVE-2026-62913 is a high-severity memory corruption vulnerability in Microsoft Exchange Server, published on 11 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

Heap-based buffer overflow in Microsoft Exchange Server allows an authorized attacker to execute code over a network.

Weakness: CWE-122

Which versions are affected by CVE-2026-62913?

It affects 2 products.

Products include Microsoft Exchange Server, Microsoft Exchange Server Subscription Edition.

How do I fix CVE-2026-62913?

No fix has been published for CVE-2026-62913 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-2026-62913 being exploited?

There is no known exploitation of CVE-2026-62913 in the wild and no public exploit code.

All Microsoft Exchange Server vulnerabilities

Sources

Also known as GHSA-9c4p-v976-93rw.

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