Microsoft Windows up to Server 2025 Ancillary Function Driver for WinSock use after free

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.
5.3$25k-$100k0.69+

Summaryinfo

A vulnerability described as problematic has been identified in Microsoft Windows. Affected is an unknown function of the component Ancillary Function Driver for WinSock. Executing a manipulation can lead to use after free. This vulnerability is handled as CVE-2026-50312. It is possible to launch the attack on the local host. There is not any exploit available.

Detailsinfo

A vulnerability classified as problematic was found in Microsoft Windows. This vulnerability affects an unknown code block of the component Ancillary Function Driver for WinSock. The manipulation with an unknown input leads to a use after free vulnerability. The CWE definition for the vulnerability is CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

Use after free in Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally.

The advisory is available at msrc.microsoft.com. This vulnerability was named CVE-2026-50312 since 06/04/2026. The exploitation appears to be easy. Local access is required to approach this attack. The technical details are unknown and an exploit is not available. The structure of the vulnerability defines a possible price range of USD $25k-$100k at the moment (estimation calculated on 07/14/2026).

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.3
VulDB Meta Temp Score: 5.3

VulDB Base Score: 5.3
VulDB Temp Score: 5.3
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

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

Exploitinginfo

Class: Use after free
CWE: CWE-416 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: No

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔒

Timelineinfo

06/04/2026 CVE reserved
07/14/2026 +40 days Advisory disclosed
07/14/2026 +0 days VulDB entry created
07/14/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: microsoft.com
Product: microsoft.com

Advisory: msrc.microsoft.com
Status: Confirmed

CVE: CVE-2026-50312 (🔒)
GCVE (CVE): GCVE-0-2026-50312
GCVE (VulDB): GCVE-100-378586
scip Labs: https://www.scip.ch/en/?labs.20161215

Entryinfo

Created: 07/14/2026 22:08
Changes: 07/14/2026 22:08 (53)
Complete: 🔍
Cache ID: 216::103

If you want to get best quality of vulnerability data, you may have to visit VulDB.

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