Jan 2026: Windows Ancillary Function Driver for WinSock Elevation of Privilege Vulnerability
CVE-2026-20810 Published on January 13, 2026
Windows Ancillary Function Driver for WinSock Elevation of Privilege Vulnerability
Free of memory not on the heap in Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally.
Weakness Type
Free of Memory not on the Heap
The application calls free() on a pointer to memory that was not allocated using associated heap allocation functions such as malloc(), calloc(), or realloc(). When free() is called on an invalid pointer, the program's memory management data structures may become corrupted. This corruption can cause the program to crash or, in some circumstances, an attacker may be able to cause free() to operate on controllable memory locations to modify critical program variables or execute code.
Products Associated with CVE-2026-20810
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Affected Versions
Microsoft Windows 10 Version 1809:- Version 10.0.17763.0 and below 10.0.17763.8276 is affected.
- Version 10.0.19044.0 and below 10.0.19044.6809 is affected.
- Version 10.0.19045.0 and below 10.0.19045.6809 is affected.
- Version 10.0.17763.0 and below 10.0.17763.8276 is affected.
- Version 10.0.17763.0 and below 10.0.17763.8276 is affected.
Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.