CVE-2025-21311: CWE-303: Incorrect Implementation of Authentication Algorithm in Microsoft Windows 11 Version 24H2
Windows NTLM V1 Elevation of Privilege Vulnerability
AI Analysis
Technical Summary
This vulnerability, identified as CVE-2025-21311 and classified under CWE-303 (Incorrect Implementation of Authentication Algorithm), affects Windows 11 Version 24H2 (build 10.0.26100.0). It involves a flaw in the NTLM V1 authentication mechanism that can be exploited remotely without authentication or user interaction to elevate privileges. The CVSS v3.1 base score is 9.8, indicating a critical severity with high impact on confidentiality, integrity, and availability. Microsoft has released an official fix for this vulnerability as documented in their security update guide.
Potential Impact
Successful exploitation of this vulnerability could allow an unauthenticated attacker to elevate privileges on a vulnerable Windows 11 system, potentially leading to full system compromise with complete control over confidentiality, integrity, and availability of the affected system.
Mitigation Recommendations
An official fix is available from Microsoft. Users and administrators should apply the security update provided by Microsoft for Windows 11 Version 24H2 (build 10.0.26100.0) as soon as possible. Refer to the Microsoft security update guide at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-21311 for detailed patch information and deployment instructions.
CVE-2025-21311: CWE-303: Incorrect Implementation of Authentication Algorithm in Microsoft Windows 11 Version 24H2
Description
Windows NTLM V1 Elevation of Privilege Vulnerability
CVSS v3.1
Score 9.8critical
Affected software
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability, identified as CVE-2025-21311 and classified under CWE-303 (Incorrect Implementation of Authentication Algorithm), affects Windows 11 Version 24H2 (build 10.0.26100.0). It involves a flaw in the NTLM V1 authentication mechanism that can be exploited remotely without authentication or user interaction to elevate privileges. The CVSS v3.1 base score is 9.8, indicating a critical severity with high impact on confidentiality, integrity, and availability. Microsoft has released an official fix for this vulnerability as documented in their security update guide.
Potential Impact
Successful exploitation of this vulnerability could allow an unauthenticated attacker to elevate privileges on a vulnerable Windows 11 system, potentially leading to full system compromise with complete control over confidentiality, integrity, and availability of the affected system.
Mitigation Recommendations
An official fix is available from Microsoft. Users and administrators should apply the security update provided by Microsoft for Windows 11 Version 24H2 (build 10.0.26100.0) as soon as possible. Refer to the Microsoft security update guide at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-21311 for detailed patch information and deployment instructions.
Technical Details
- Data Version
- 5.1
- Assigner Short Name
- microsoft
- Date Reserved
- 2024-12-10T23:54:12.953Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- official-fix
- Vendor Advisory Urls
- [{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-21311","vendor":"Microsoft"}]
Threat ID: 68c0c0d09ed239a66badfd0e
Added to database: 09/10/2025, 00:05:36 UTC
Last enriched: 06/10/2026, 09:53:01 UTC
Last updated: 09/10/2026, 19:36:49 UTC
Views: 360
Community Reviews
0 reviewsCrowdsource mitigation strategies, share intel context, and vote on the most helpful responses. Sign in to add your voice and help keep defenders ahead.
Want to contribute mitigation steps or threat intel context? Sign in or create an account to join the community discussion.
Actions
Updates to AI analysis require Pro Console access. Upgrade inside Console → Billing.
External Links
Need more coverage?
Upgrade to Pro Console for AI refresh and higher limits.
For incident response and remediation, OffSeq services can help resolve threats faster.
Latest Threats
Check if your credentials are on the dark web
Instant breach scanning across billions of leaked records. Free tier available.