CVE-2025-66266 CRITICAL

CVE-2025-66266: Insecure SYSTEM Service Permissions in UPSilon2000V6.0 (RupsMon.exe) leading to trivial Local Privilege Escalation

Vendor Megatec Taiwan
Product UPSilon2000V6.0
Weakness CWE-269
Published November 26, 2025
Last update November 26, 2025

CVSS base score

9.3/10
Attack vector Local
Attack complexity Low
Privileges required None
User interaction None
Confidentiality
Integrity

CVSS vector

CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:H/SI:H/SA:N

What the vulnerability does

01Description

The RupsMon.exe service executable in UPSilon 2000 has insecure permissions, allowing the 'Everyone' group Full Control. A local attacker can replace the executable with a malicious binary to execute code with SYSTEM privileges or simply change the config path of the service to a command; starting and stopping the service to immediately achieve code execution and privilege escalation

Key dates

02Disclosure timeline

November 26, 2025 CVE published
November 26, 2025 Record updated