CVE-2026-50508: Windows NTLM Spoofing Vulnerability

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 12.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-06-09 · updated 2026-09-24
Weakness: CWE-200

Description

Exposure of sensitive information to an unauthorized actor in Windows NTLM allows an unauthorized attacker to perform spoofing over a network.

Affected products

Microsoft Windows 10 1607: before 10.0.14393.9234 — fixed in 10.0.14393.9234
Microsoft Windows 11: before 10.0.22631.7219 — fixed in 10.0.22631.7219
Microsoft Windows Server 2004: before 10.0.19045.7417 — fixed in 10.0.19045.7417
Microsoft Windows Server 2012: r2
Microsoft Windows Server 2016: before 10.0.14393.9234 — fixed in 10.0.14393.9234
Microsoft Windows Server 2022: before 10.0.20348.5256 — fixed in 10.0.20348.5256
Microsoft Windows 10 1607: from 10.0.14393.0 before 10.0.14393.9234 — fixed in 10.0.14393.9234
Microsoft Windows 11: from 10.0.22621.0 before 10.0.22631.7219 — fixed in 10.0.22631.7219
Microsoft Windows Server 2012: from 6.2.9200.0 before 6.2.9200.26132 — fixed in 6.2.9200.26132
Microsoft Windows Server 2012 R2: from 6.3.9600.0 before 6.3.9600.23228 — fixed in 6.3.9600.23228
Microsoft Windows Server 2016: from 10.0.14393.0 before 10.0.14393.9234 — fixed in 10.0.14393.9234
Microsoft Windows Server 2022: from 10.0.20348.0 before 10.0.20348.5256 — fixed in 10.0.20348.5256
Microsoft Windows Server version 2004: from 10.0.0 before 10.0.19045.7417 — fixed in 10.0.19045.7417

How to fix

Upgrade to a fixed version: Microsoft Windows 10 1607 10.0.14393.9234; Microsoft Windows 11 10.0.22631.7219; Microsoft Windows Server 2004 10.0.19045.7417; Microsoft Windows Server 2016 10.0.14393.9234; Microsoft Windows Server 2022 10.0.20348.5256; Microsoft Windows 10 1607 10.0.14393.9234; Microsoft Windows 11 10.0.22631.7219; Microsoft Windows Server 2012 6.2.9200.26132; Microsoft Windows Server 2012 R2 6.3.9600.23228; Microsoft Windows Server 2016 10.0.14393.9234; Microsoft Windows Server 2022 10.0.20348.5256; Microsoft Windows Server version 2004 10.0.19045.7417. Check the vendor advisory for mitigations.

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-50508

Get alerted when CVE-2026-50508 or the next vulnerability affects your stack