CVE-2025-21311

Windows NTLM V1 Elevation of Privilege Vulnerability

CVE-2025-21311 is fixed in 6 products on 2 platforms, first by KB5050009, released January 14, 2025. It is not reported as exploited. Patch Radar priority: Urgent.

UrgentFixed on 2 platforms

CVSS

9.8

Critical

Exploitation

None reported

Exploitation Less Likely

CISA KEV

Not listed

Not in the Known Exploited Vulnerabilities catalog

EPSS

0.0226

83rd percentile

Windows NTLM V1 Elevation of Privilege Vulnerability

Where it's fixed

Product	Fixed in	Fix	Released
Microsoft
Windows 11 Version 24H2 for ARM64-based Systems	26100.2894	KB5050009	Jan 14, 2025
Windows 11 Version 24H2 for x64-based Systems	26100.2894	KB5050009	Jan 14, 2025
Windows Server 2022, 23H2 Edition (Server Core installation)	25398.1369	KB5049984	Jan 14, 2025
Windows Server 2025	26100.2894	KB5050009	Jan 14, 2025
Windows Server 2025 (Server Core installation)	26100.2894	KB5050009	Jan 14, 2025
Linux
squid · Debian 14	7.1-1	DEBIAN-CVE-2025-21311	Jan 14, 2025

Details

Published
January 14, 2025
Weakness
Incorrect Implementation of Authentication Algorithm
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Vendor advisory
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-21311

For tools and AI agents

This page as data: JSON · Markdown

Link to this page

If this page saved you time, a link to it in your ticket, advisory or write-up helps others find it.

HTML

<a href="https://patchblox.com/security/cve/CVE-2025-21311">CVE-2025-21311 on Patchblox Patch Radar</a>

Reusing the data? How to credit Patch Radar.

Is this on your machines?

Patchblox finds every install below the fixed version on Windows, macOS and Linux, and updates them through your release rings.

Get a demo

Patch Radar data is free to use with attribution. Terms and how to credit it.

Product names, logos and trademarks shown on Patch Radar belong to their respective owners. They are used only to identify the software each security fix applies to and to help readers find their platform. Their use does not imply any affiliation with, or endorsement by, those owners, and Patchblox is not affiliated with any of them.