Jan 2026: Windows Management Services Elevation of Privilege Vulnerability
CVE-2026-20861 Published on January 13, 2026
Windows Management Services Elevation of Privilege Vulnerability
Concurrent execution using shared resource with improper synchronization ('race condition') in Windows Management Services allows an authorized attacker to elevate privileges locally.
Weakness Types
What is a Race Condition Vulnerability?
The program contains a code sequence that can run concurrently with other code, and the code sequence requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence that is operating concurrently.
CVE-2026-20861 has been classified to as a Race Condition vulnerability or weakness.
What is a Dangling pointer Vulnerability?
Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code.
CVE-2026-20861 has been classified to as a Dangling pointer vulnerability or weakness.
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-2026-20861 has been classified to as a Double-free vulnerability or weakness.
Products Associated with CVE-2026-20861
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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 10.0.22631.0 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 10.0.17763.0 and below 10.0.17763.8276 is affected.
- Version 10.0.17763.0 and below 10.0.17763.8276 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.