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

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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7.7$5k-$25k0.00+

Summaryinfo

A vulnerability identified as very critical has been detected in Microsoft Windows. This impacts an unknown function of the component Ancillary Function Driver. This manipulation causes use after free. This vulnerability is tracked as CVE-2026-88242. The attack is restricted to local execution. No exploit exists. It is recommended to apply a patch to fix this issue.

Detailsinfo

A vulnerability classified as very critical was found in Microsoft Windows. Affected by this vulnerability is some unknown functionality of the component Ancillary Function Driver. The manipulation with an unknown input leads to a use after free vulnerability. The CWE definition for the vulnerability is CWE-416. The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

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

It is possible to read the advisory at msrc.microsoft.com. This vulnerability is known as CVE-2026-88242 since 09/10/2026. The exploitation appears 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 at the moment (estimation calculated on 11/11/2026).

Applying a patch is able to eliminate this problem.

Be aware that VulDB is the high quality source 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: 7.9
VulDB Meta Temp Score: 7.7

VulDB Base Score: 8.8
VulDB Temp Score: 8.4
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 7.0
CNA Vector (microsoft): 🔒

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: Patch
Status: 🔍

0-Day Time: 🔒

Timelineinfo

09/10/2026 CVE reserved
11/10/2026 +61 days VulDB entry created
11/11/2026 +0 days Advisory disclosed
11/11/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: microsoft.com
Product: microsoft.com

Advisory: msrc.microsoft.com
Status: Confirmed

CNA: microsoft
CVE: CVE-2026-88242 (🔒)

GCVE (CVE): GCVE-0-2026-88242
GCVE (VulDB): GCVE-100-435367
scip Labs: https://www.scip.ch/en/?labs.20161215

Entryinfo

Created: 11/11/2026 00:18
Changes: 11/11/2026 00:18 (63)
Complete: 🔍
Cache ID: 216::103

Be aware that VulDB is the high quality source for vulnerability data.

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