CVE-2025-48802: Windows SMB Server Spoofing Vulnerability

Severity: medium (CVSS 6.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.9% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-07-08 · updated 2026-06-17
Weakness: CWE-295

Description

Improper certificate validation in Windows SMB allows an authorized attacker to perform spoofing over a network.

Affected products

Microsoft Windows 11: before 10.0.22621.5624 — fixed in 10.0.22621.5624
Microsoft Windows 11: before 10.0.22631.5624 — fixed in 10.0.22631.5624
Microsoft Windows Server 2022: before 10.0.20348.3932 — fixed in 10.0.20348.3932
Microsoft Windows Server 2022, 23H2 Edition (Server Core installation): before 10.0.25398.1732 — fixed in 10.0.25398.1732
Microsoft Windows 11: from 10.0.22621.0 before 10.0.22621.5624 — fixed in 10.0.22621.5624
Microsoft Windows 11 version 22H3: from 10.0.22631.0 before 10.0.22631.5624 — fixed in 10.0.22631.5624
Microsoft Windows 11: from 10.0.22631.0 before 10.0.22631.5624 — fixed in 10.0.22631.5624
Microsoft Windows Server 2022: from 10.0.20348.0 before 10.0.20348.3932 — fixed in 10.0.20348.3932
Microsoft Windows Server 2022, 23H2 Edition (Server Core installation): from 10.0.25398.0 before 10.0.25398.1732 — fixed in 10.0.25398.1732

How to fix

Upgrade to a fixed version: Microsoft Windows 11 10.0.22621.5624; Microsoft Windows 11 10.0.22631.5624; Microsoft Windows Server 2022 10.0.20348.3932; Microsoft Windows Server 2022, 23H2 Edition (Server Core installation) 10.0.25398.1732; Microsoft Windows 11 10.0.22621.5624; Microsoft Windows 11 version 22H3 10.0.22631.5624; Microsoft Windows 11 10.0.22631.5624; Microsoft Windows Server 2022 10.0.20348.3932; Microsoft Windows Server 2022, 23H2 Edition (Server Core installation) 10.0.25398.1732. Check the vendor advisory for mitigations.

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-48802

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