CVE-2025-63685: Quark Cloud Drive

Critical severity, CVSS 9.8. EPSS: 0.4% chance of exploitation in the next 30 days.

Quark Cloud Drive v3.23.2 has a DLL Hijacking vulnerability. This vulnerability stems from the insecure loading of system libraries. Specifically, the application does not validate the path or signature of [regsvr32.exe] it loads. An attacker can place a crafted malicious DLL in the application's startup directory, which will be loaded and executed when the user launches the program.

Affected products

• Quark Quark Cloud Drive: version 3.23.2 only

Published 2025-11-20. Last modified 2026-06-17.