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

Severity: critical (CVSS 9.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.0% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-09-08 · updated 2026-10-14
Weakness: CWE-416

Description

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

Affected products

Microsoft Windows Server 2012: r2
Microsoft Windows Server 2016: before 10.0.14393.9512 — fixed in 10.0.14393.9512
Microsoft Windows Server 2019: before 10.0.17763.9245 — fixed in 10.0.17763.9245
Microsoft Windows Server 2022: before 10.0.20348.5622 — fixed in 10.0.20348.5622
Microsoft Windows Server 2025: before 10.0.26100.33438 — fixed in 10.0.26100.33438
Microsoft Windows Server 2012: from 6.2.9200.0 before 6.2.9200.26349 — fixed in 6.2.9200.26349
Microsoft Windows Server 2012 R2: from 6.3.9600.0 before 6.3.9600.23398 — fixed in 6.3.9600.23398
Microsoft Windows Server 2016: from 10.0.14393.0 before 10.0.14393.9512 — fixed in 10.0.14393.9512
Microsoft Windows Server 2019: from 10.0.17763.0 before 10.0.17763.9245 — fixed in 10.0.17763.9245
Microsoft Windows Server 2022: from 10.0.20348.0 before 10.0.20348.5622 — fixed in 10.0.20348.5622
Microsoft Windows Server 2025: from 10.0.26100.0 before 10.0.26100.33438 — fixed in 10.0.26100.33438

How to fix

Upgrade to a fixed version: Microsoft Windows Server 2016 10.0.14393.9512; Microsoft Windows Server 2019 10.0.17763.9245; Microsoft Windows Server 2022 10.0.20348.5622; Microsoft Windows Server 2025 10.0.26100.33438; Microsoft Windows Server 2012 6.2.9200.26349; Microsoft Windows Server 2012 R2 6.3.9600.23398; Microsoft Windows Server 2016 10.0.14393.9512; Microsoft Windows Server 2019 10.0.17763.9245; Microsoft Windows Server 2022 10.0.20348.5622; Microsoft Windows Server 2025 10.0.26100.33438. Check the vendor advisory for mitigations.

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-78445

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