This vulnerability involves a use-after-free condition in Windows Management Services on Windows 10 Version 1809 (build 10.0.17763.0). An authorized attacker with local access can exploit this flaw to elevate their privileges. The CVSS 3.1 base score is 7.8, reflecting high impact on confidentiality, integrity, and availability. Microsoft has released a temporary fix to mitigate the issue. No known exploits are reported in the wild at this time.

Successful exploitation allows an authorized local attacker to elevate privileges, potentially gaining higher system rights than intended. This can lead to full system compromise, affecting confidentiality, integrity, and availability of the affected system.

Microsoft has provided a temporary fix for this vulnerability. Users should apply the temporary fix as directed in the Microsoft advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20858. Monitor the vendor advisory for updates regarding a permanent official fix.