Critical severity · published Aug 29, 2025
CVE-2025-52856
An improper authentication vulnerability has been reported to affect VioStor
9.8
CVSS
0.7%
EPSS
No
On KEV
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
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.7% · higher than 51% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
QV
Qvr · Qnap
5.1.0 before 5.1.6; 5.1.6 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2025-52856
CVE.org
https://www.cve.org/CVERecord?id=CVE-2025-52856
Vendor Advisory
https://www.qnap.com/en/security-advisory/qsa-25-29
More from Qvr
9.8
CVE-2022-27588
We have already fixed this vulnerability in the following versions of QVR: QVR 5.1.6 build 20220401 and later
9.8
CVE-2021-38685
A command injection vulnerability has been reported to affect QNAP device, VioStor
9.8
CVE-2021-34352
A command injection vulnerability has been reported to affect QNAP device running QVR
9.8
CVE-2021-34351
A command injection vulnerability has been reported to affect QNAP device running QVR
9.8
CVE-2021-34348
A command injection vulnerability has been reported to affect QNAP device running QVR