NULL pointer dereference in QNAP Qts
CVE-2025-66281
A NULL pointer dereference vulnerability has been reported to affect several QNAP operating system versions. The remote attackers can then exploit the vulnerability to launch a denial-of-service (DoS) attack. We have already fixed the vulnerability in the following versions: QTS 5.2.9.3410 build 20260214 and later QuTS hero h5.2.9.3410 build 20260214 and later QuTS hero h5.3.4.3500 build 20260520 and later QuTS hero h6.0.0.3397 build 20260206 and later
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.2 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.005 (37.1th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 37th percentile — 37.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.005 · newest: 0.005 · change: 0.000
Affected products
- QNAP Qts
- QNAP Quts Hero
- QNAP Systems Inc. Qts — versions 5.2.0
- QNAP Systems Inc. Quts Hero — versions h5.2.0, h5.3.0
Weakness classification (CWE)
References
- www.qnap.com/en/security-advisory/qsa-26-10 (Broken Link, Vendor Advisory)
Frequently asked questions
- What is CVE-2025-66281?
- CVE-2025-66281 is a high-severity vulnerability in QNAP Qts, classified under NULL Pointer Dereference. CVSS score: 7.2/10. Published 2026-06-10.
- How severe is CVE-2025-66281?
- High severity. CVSS v3 base score is 7.2 out of 10.