CVE-2025-59284: Windows NTLM Spoofing Vulnerability

Severity: medium (CVSS 5.5 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: 2025-10-14 · updated 2026-10-18
Weakness: CWE-200

Description

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

Affected products

Microsoft Windows 11: before 10.0.22621.6060 — fixed in 10.0.22621.6060
Microsoft Windows 11: before 10.0.22631.6060 — fixed in 10.0.22631.6060
Microsoft Windows 11: before 10.0.26100.6899 — fixed in 10.0.26100.6899
Microsoft Windows 11 25H2: before 10.0.26200.6899 — fixed in 10.0.26200.6899
Microsoft Windows Server 2025: before 10.0.26100.6899 — fixed in 10.0.26100.6899
Microsoft Windows 11: from 10.0.22621.0 before 10.0.22621.6060 — fixed in 10.0.22621.6060
Microsoft Windows 11 version 22H3: from 10.0.22631.0 before 10.0.22631.6060 — fixed in 10.0.22631.6060
Microsoft Windows 11: from 10.0.22631.0 before 10.0.22631.6060 — fixed in 10.0.22631.6060
Microsoft Windows 11: from 10.0.26100.0 before 10.0.26100.6899 — fixed in 10.0.26100.6899
Microsoft Windows 11 25H2: from 10.0.26200.0 before 10.0.26200.6899 — fixed in 10.0.26200.6899
Microsoft Windows Server 2025: from 10.0.26100.0 before 10.0.26100.6899 — fixed in 10.0.26100.6899

How to fix

Upgrade to a fixed version: Microsoft Windows 11 10.0.22621.6060; Microsoft Windows 11 10.0.22631.6060; Microsoft Windows 11 10.0.26100.6899; Microsoft Windows 11 25H2 10.0.26200.6899; Microsoft Windows Server 2025 10.0.26100.6899; Microsoft Windows 11 10.0.22621.6060; Microsoft Windows 11 version 22H3 10.0.22631.6060; Microsoft Windows 11 10.0.22631.6060; Microsoft Windows 11 10.0.26100.6899; Microsoft Windows 11 25H2 10.0.26200.6899; Microsoft Windows Server 2025 10.0.26100.6899. Check the vendor advisory for mitigations.

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-59284

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