Heap-Based Buffer Overflow in Windows Ancillary Function Driver for WinSock
CVE-2025-59242

7.8HIGH

Key Information:

Vendor

Microsoft
Status
Windows 10 Version 1809
Windows Server 2019
Windows Server 2019 (server Core Installation)
Windows Server 2022
Vendor
CVE Published:
14 October 2025

What is CVE-2025-59242?

A buffer overflow vulnerability exists in the Windows Ancillary Function Driver for WinSock, which can be exploited by an authorized attacker to gain elevated privileges on the affected system. If successfully exploited, this vulnerability can allow the attacker to execute arbitrary code with higher access levels, potentially compromising the integrity and confidentiality of the system.

Affected Version(s)

Windows 10 Version 1507 32-bit Systems 10.0.10240.0 < 10.0.10240.21161

Windows 10 Version 1607 32-bit Systems 10.0.14393.0 < 10.0.14393.8519

Windows 10 Version 1809 32-bit Systems 10.0.17763.0 < 10.0.17763.7919

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE...
vendor-advisory

CVSS V3.1

Score:
7.8
Severity:
HIGH
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Local
Attack Complexity:
Low
Privileges Required:
Low
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

JSON
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CVE-2025-59242 : Heap-Based Buffer Overflow in Windows Ancillary Function Driver for WinSock