CVE-2026-6643: Asustor Data Master

Critical severity, CVSS 9.9. EPSS: 0.8% chance of exploitation in the next 30 days.

A stack-based buffer overflow vulnerability was found in the VPN Clients on the ADM. The issue stems from the use of unbounded sscanf() and passing user-controlled data directly to printf(). Due to the lack of PIE and Stack Canary protections, an authenticated remote attacker can exploit these to execute arbitrary code as the web server user. Affected products and versions include: from ADM 4.1.0 through ADM 4.3.3.RR42 as well as from ADM 5.0.0 through ADM 5.1.2.REO1.

Affected products

• Asustor Data Master: from 4.1.0.rhu2, before 4.3.3.RR42 (fixed in 4.3.3.RR42); from 5.0.0.ra82, before 5.1.2.reo1 (fixed in 5.1.2.reo1)

Published 2026-04-20. Last modified 2026-06-17.