CVE-2026-83871 Microsoft OpenSSH for Windows Elevation of Privilege Vulnerability

High 7.0 Published Updated

A heap-based buffer overflow in Microsoft OpenSSH for Windows allows an authorized local attacker to elevate privileges.

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

What is CVE-2026-83871?

CVE-2026-83871 is a high-severity memory corruption vulnerability in Microsoft Windows 10 1809, published on 13 Oct 2026. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

Heap-based buffer overflow in OpenSSH for Windows allows an authorized attacker to elevate privileges locally.

Weakness: CWE-367, CWE-122

Which versions are affected by CVE-2026-83871?

It affects 11 products.

Products include Microsoft Windows 10 1809, Microsoft Windows 10 21h2, Microsoft Windows 10 22h2, Microsoft Windows 11 23h2, Microsoft Windows 11 24h2, Microsoft Windows 11 25h2 and 5 more.

How do I fix CVE-2026-83871?

No fix has been published for CVE-2026-83871 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-2026-83871 being exploited?

There is no known exploitation of CVE-2026-83871 in the wild and no public exploit code.

All Microsoft Windows 10 1809 vulnerabilities

Sources

Also known as GHSA-v5h7-r869-8r86.

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