CVE-2025-52856 CRITICAL

CVE-2025-52856: VioStor

Vendor Qnap Systems Inc.
Product VioStor
Weakness CWE-287 · Improper authentication
Published August 29, 2025
Last update February 26, 2026

CVSS base score

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

CVSS vector

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

What the vulnerability does

01Description

An improper authentication vulnerability has been reported to affect VioStor. If a remote attacker, they can then exploit the vulnerability to compromise the security of the system. We have already fixed the vulnerability in the following version: VioStor 5.1.6 build 20250621 and later

Key dates

02Disclosure timeline

August 29, 2025 CVE published
February 26, 2026 Record updated