CVE-2025-52856: QNAP Systems VioStor · CWE-287
Affects QNAP Systems VioStorSource CVE Database V5
Not known to be exploited · CVSS 9.3 Critical.
Data as of 25 Oct 2026, 18:53 UTC
- EPSS
- 0.6% chance of exploitation in 30 days – higher than 51% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 29 Aug 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-25.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| QNAP Systems Inc. VioStor | Affected
| Fixed in– |
AI-suggested
To mitigate CVE-2025-52856, organizations should immediately upgrade affected VioStor systems to version 5.1.6 build 20250621 or later, where the vulnerability is patched. Until patching is complete, restrict network access to VioStor management interfaces by implementing network segmentation and firewall rules to limit exposure to trusted IP addresses only. Disable any unnecessary remote access services and enforce strong network-level authentication controls such as VPNs or IPsec tunnels. Monitor network traffic and system logs for unusual authentication attempts or access patterns indicative of exploitation attempts. Employ intrusion detection/prevention systems (IDS/IPS) with updated signatures to detect potential exploitation. Conduct regular vulnerability scans and penetration tests focusing on VioStor devices to identify residual risks. Educate security teams about this specific vulnerability to ensure rapid incident response if exploitation is suspected. Finally, maintain an inventory of all VioStor deployments and ensure consistent patch management practices to prevent similar vulnerabilities from remaining unaddressed.
Description
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