CVE-2026-70343 Microsoft MPEG-2 Video Extension Remote Code Execution Vulnerability

High 8.8 Published Updated

Heap-based buffer overflow in Microsoft MPEG-2 Video Extension allows remote attackers to execute arbitrary code.

Exploited in the wild
Not known
Login needed
Not needed
Attackable
Over the internet
Victim action needed
A user has to click or open something
Fix
None listed

What is CVE-2026-70343?

CVE-2026-70343 is a high-severity memory corruption vulnerability in Microsoft MPEG-2 Video Extension, published on 13 Oct 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

Official description

Heap-based buffer overflow in Microsoft MPEG-2 Video Extension allows an unauthorized attacker to execute code over a network.

Weakness: CWE-122

Which versions are affected by CVE-2026-70343?

How do I fix CVE-2026-70343?

No fix has been published for CVE-2026-70343 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-2026-70343 being exploited?

There is no known exploitation of CVE-2026-70343 in the wild and no public exploit code.

Sources

Also known as GHSA-cghg-475q-8v9j.

Is CVE-2026-70343 in your software?

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