CVE-2026-83518 RPC Runtime Elevation of Privilege Vulnerability

High 7.8 Published 13 Oct 2026 Updated 29 Oct 2026

A heap-based buffer overflow in the Windows RPC Runtime 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-2026-83518?

CVE-2026-83518 is a high-severity memory corruption vulnerability in Microsoft Windows 11 23h2, 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 RPC Runtime allows an authorized attacker to elevate privileges locally.

Weakness: CWE-122

Which versions are affected by CVE-2026-83518?

It affects 4 products.

Products include Microsoft Windows 11 23h2, Microsoft Windows 11 24h2, Microsoft Windows 11 25h2, Microsoft Windows 11 26h1.

How do I fix CVE-2026-83518?

No fix has been published for CVE-2026-83518 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-2026-83518 being exploited?

There is no known exploitation of CVE-2026-83518 in the wild and no public exploit code.

All Microsoft Windows 11 23h2 vulnerabilities

Sources

Also known as GHSA-jr84-qg44-hh67.