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3.3
LOW CVSS 3.1
CVE-2026-21249
Windows NTLM Spoofing Vulnerability
Description

External control of file name or path in Windows NTLM allows an unauthorized attacker to perform spoofing locally.

INFO

Published Date :

Feb. 10, 2026, 6:16 p.m.

Last Modified :

Feb. 10, 2026, 9:51 p.m.

Remotely Exploit :

No

Source :

[email protected]
Affected Products

The following products are affected by CVE-2026-21249 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Microsoft windows_server_2016
2 Microsoft windows_server_2019
3 Microsoft windows_10_1607
4 Microsoft windows_10_1809
5 Microsoft windows_10_21h2
6 Microsoft windows_10_22h2
7 Microsoft windows_server_2022
8 Microsoft windows_11_23h2
9 Microsoft windows_server_23h2
10 Microsoft windows_server_2012_r2
11 Microsoft windows_11_24h2
12 Microsoft windows_server_2025
13 Microsoft windows_11_25h2
14 Microsoft windows_11_26h1
: Total Affected Vendor : 1 | Products : 14
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 LOW [email protected]
Solution
Address file path spoofing vulnerabilities by applying vendor patches and updating system configurations.
  • Apply vendor-supplied security patches promptly.
  • Update Windows NTLM configurations.
  • Review and restrict file path access.
  • Monitor system for unauthorized access.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-21249.

URL Resource
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21249
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-21249 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-21249 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-21249 vulnerability anywhere in the article.

  • The Cyber Express
Microsoft Patch Tuesday February Update Flags Exchange and Azure Vulnerabilities as High-Priority Risks

Microsoft Patch Tuesday February 2026 addressed 54 vulnerabilities including six zero-days across Windows, Office, Azure services, Exchange Server, and developer tools. The latest patch update, rollou ... Read more

Published Date: Feb 11, 2026 (4 hours, 51 minutes ago)
  • Zero Day Initiative
The February 2026 Security Update Review

I have survived the biggest Pwn2Own ever, but I’m back in Tokyo for the second Patch Tuesday of 2026. My location never stops Patch Tuesday from coming, so let’s take a look at the latest security pat ... Read more

Published Date: Feb 10, 2026 (17 hours, 5 minutes ago)

Results are limited to the first 20 news articles due to potential performance issues.

The following table lists the changes that have been made to the CVE-2026-21249 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Feb. 10, 2026

    Action Type Old Value New Value
    Added Description External control of file name or path in Windows NTLM allows an unauthorized attacker to perform spoofing locally.
    Added CVSS V3.1 AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N
    Added CWE CWE-73
    Added Reference https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21249
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
Vulnerability Scoring Details
Base CVSS Score: 3.3
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality Impact
Integrity Impact
Availability Impact