Jan 2026: Win32k Elevation of Privilege Vulnerability
CVE-2026-20863 Published on January 13, 2026
Win32k Elevation of Privilege Vulnerability
Double free in Windows Win32K - ICOMP allows an authorized attacker to elevate privileges locally.
Weakness Type
What is a Double-free Vulnerability?
The product calls free() twice on the same memory address, potentially leading to modification of unexpected memory locations. When a program calls free() twice with the same argument, the program's memory management data structures become corrupted. This corruption can cause the program to crash or, in some circumstances, cause two later calls to malloc() to return the same pointer. If malloc() returns the same value twice and the program later gives the attacker control over the data that is written into this doubly-allocated memory, the program becomes vulnerable to a buffer overflow attack.
CVE-2026-20863 has been classified to as a Double-free vulnerability or weakness.
Products Associated with CVE-2026-20863
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Affected Versions
Microsoft Windows 11 version 22H3:- Version 10.0.22631.0 and below 10.0.22631.6491 is affected.
- Version 10.0.22631.0 and below 10.0.22631.6491 is affected.
- Version 10.0.26100.0 and below 10.0.26100.7623 is affected.
- Version 10.0.26200.0 and below 10.0.26200.7623 is affected.
- Version 10.0.20348.0 and below 10.0.20348.4648 is affected.
- Version 10.0.25398.0 and below 10.0.25398.2092 is affected.
- Version 10.0.26100.0 and below 10.0.26100.32230 is affected.
- Version 10.0.26100.0 and below 10.0.26100.32230 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.