Windows Error Reporting Service Vulnerability Grants Elevated Privileges

EXECUTIVE SUMMARY:

A newly disclosed vulnerability CVE-2026-20817 in the Windows Error Reporting Service (WER) enables attackers with standard user privileges to locally escalate their access to SYSTEM‑level control by sending specially crafted messages to the services inter‑process communication interface, exploiting improper permission handling in WER and bypassing expected authorization checks; successful exploitation can grant elevated privileges sufficient for credential theft, unauthorized command execution, and full system compromise if left unpatched, making timely deployment of vendor‑provided security updates and enhanced monitoring of anomalous local privilege escalation attempts for protecting affected Windows systems. The vulnerability has a CVSS score of 7.8.