Vulnerability in QNAP Qts
CVE-2025-53406
A use of externally-controlled format string vulnerability has been reported to affect several QNAP operating system versions. If a remote attacker gains an administrator account, they can then exploit the vulnerability to obtain secret data or modify memory. We have already fixed the vulnerability in the following versions: QTS 5.2.6.3195 build 20250715 and later QuTS hero h5.2.6.3195 build 20250715 and later
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N.
EPSS exploit prediction
EPSS: 0.004 (27.7th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 28th percentile — 27.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.004 · change: +0.000
Affected products
- QNAP Qts — versions 5.2.0.2737, 5.2.0.2744, 5.2.0.2782
- QNAP Quts Hero — versions h5.2.0.2737, h5.2.0.2782, h5.2.0.2789
- QNAP Systems Inc. Qts — versions 5.2.x
- QNAP Systems Inc. Quts Hero — versions h5.2.x
Weakness classification (CWE)
Public proof-of-concept exploits
References
- www.qnap.com/en/security-advisory/qsa-25-36 (Vendor Advisory)
Frequently asked questions
- What is CVE-2025-53406?
- CVE-2025-53406 is a medium-severity vulnerability in QNAP Qts, classified under Use of Externally-Controlled Format String. CVSS score: 6.5/10. Published 2025-10-03.
- How severe is CVE-2025-53406?
- Medium severity. CVSS v3 base score is 6.5 out of 10.
- Is CVE-2025-53406 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.