MSRC-CVE-2026-78445 — Windows Services for NFS ONCRPC XDR Driver Remote Code Execution Vulnerability

Summary

Impact: Remote Code Execution. Microsoft rating: Critical. Not known to be exploited — Exploitation Less Likely. Customer action: Required.

Details

How could an attacker exploit this vulnerability?
This vulnerability could be exploited over the network by making an unauthenticated, specially crafted call to a Network File System (NFS) service to trigger a Remote Code Execution (RCE).

Security updates
10.0.17763.9245 — https://support.microsoft.com/help/5122876
10.0.20348.5622 — https://support.microsoft.com/help/5122882
10.0.26100.33438 — https://support.microsoft.com/help/5122871
10.0.14393.9512 — https://support.microsoft.com/help/5123099
6.2.9200.26349 — https://support.microsoft.com/help/5123065
6.3.9600.23398 — https://support.microsoft.com/help/5123066

Vulnerabilities 1

Critical 9.8

CVE-2026-78445

Windows Services for NFS ONCRPC XDR Driver Remote Code Execution Vulnerability

Use after free in Windows Services for NFS ONCRPC XDR Driver allows an unauthorized attacker to execute code over a network.

Microsoft Windows Server 2019 Windows Server 2019 (Server Core installation) Windows Server 2022 Windows

Sep 8, 2026

Revision history

2026-09-08 #1
Information published.

References

CVE-2026-78445 Windows Services for NFS ONCRPC XDR Driver Remote Code Execution Vulnerability - HTML
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-78445
Microsoft Exploitability Index
https://www.microsoft.com/en-us/msrc/exploitability-index?rtc=1
Microsoft Support Lifecycle
https://support.microsoft.com/lifecycle
Common Vulnerability Scoring System
https://www.first.org/cvss