Buffer overflow in QNAP Qts
CVE-2025-66280
An integer overflow or wraparound 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 compromise the security of the system. 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
Vulnerability class: Buffer Overflow
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: 0.004 (35.4th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 35th percentile — 35.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · 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-2025-66280?
- CVE-2025-66280 is a high-severity vulnerability in QNAP Qts, classified under Stack-based Buffer Overflow. CVSS score: 7.2/10. Published 2026-06-10.
- How severe is CVE-2025-66280?
- High severity. CVSS v3 base score is 7.2 out of 10.