Microsoft Windows up to Server 2025 NTLM file inclusion

CVSS Meta Temp Score
CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.
Current Exploit Price (≈)
Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.
CTI Interest Score
Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
3.0$5k-$25k0.00

Summaryinfo

A vulnerability was found in Microsoft Windows. It has been rated as problematic. The impacted element is an unknown function of the component NTLM. The manipulation leads to file inclusion. This vulnerability is referenced as CVE-2026-21249. The attack can only be performed from a local environment. No exploit is available. To fix this issue, it is recommended to deploy a patch.

Detailsinfo

A vulnerability was found in Microsoft Windows. It has been rated as problematic. This issue affects an unknown function of the component NTLM. The manipulation with an unknown input leads to a file inclusion vulnerability. Using CWE to declare the problem leads to CWE-73. The product allows user input to control or influence paths or file names that are used in filesystem operations. Impacted is confidentiality. The summary by CVE is:

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

The weakness was published 02/10/2026 as confirmed security update guide (Website). It is possible to read the advisory at msrc.microsoft.com. The identification of this vulnerability is CVE-2026-21249. The exploitation is known to be easy. Attacking locally is a requirement. The technical details are unknown and an exploit is not publicly available. The pricing for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 02/11/2026).

Applying a patch is able to eliminate this problem. A possible mitigation has been published immediately after the disclosure of the vulnerability.

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 3.3
VulDB Meta Temp Score: 3.0

VulDB Base Score: 3.3
VulDB Temp Score: 2.9
VulDB Vector: 🔒
VulDB Reliability: 🔍

Vendor Base Score (Microsoft): 3.3
Vendor Vector (Microsoft): 🔒

CNA Base Score: 3.3
CNA Vector (Microsoft): 🔒

CVSSv2info

AVACAuCIA
💳💳💳💳💳💳
💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock

VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: File inclusion
CWE: CWE-73
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: Partially

Availability: 🔒
Status: Unproven

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

0-DayUnlockUnlockUnlockUnlock
TodayUnlockUnlockUnlockUnlock

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Patch
Status: 🔍

Reaction Time: 🔒
0-Day Time: 🔒
Exposure Time: 🔒

Timelineinfo

02/10/2026 VulDB entry created
02/10/2026 +0 days Advisory disclosed
02/10/2026 +0 days Countermeasure disclosed
02/11/2026 +1 days VulDB entry last update

Sourcesinfo

Vendor: microsoft.com
Product: microsoft.com

Advisory: msrc.microsoft.com
Status: Confirmed

CVE: CVE-2026-21249 (🔒)
GCVE (CVE): GCVE-0-2026-21249
GCVE (VulDB): GCVE-100-345275
scip Labs: https://www.scip.ch/en/?labs.20161215

Entryinfo

Created: 02/10/2026 19:15
Updated: 02/11/2026 16:35
Changes: 02/10/2026 19:15 (34), 02/10/2026 19:18 (35), 02/11/2026 16:35 (11)
Complete: 🔍
Cache ID: 216::103

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Discussion

No comments yet. Languages: en.

Please log in to comment.

Want to know what is going to be exploited?

We predict KEV entries!