Cyber Resilience

CVE-2025-66281

Medium

Published: 10 June 2026

Published
10 June 2026
Modified
15 June 2026
KEV Added
—
Patch
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CVSS Score v4 6.9 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.0033 25.1th percentile
Risk Priority 14 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2025-66281 is a medium-severity NULL Pointer Dereference (CWE-476) vulnerability in Qnap Quts Hero. Its CVSS base score is 6.9 (Medium).

Operationally, ranked at the 25.1th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

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…

more

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

CWE(s)
CWE-476

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

qnap
qts
5.2.0.2737 — 5.2.9.3410
qnap
quts hero
h5.2.0.2737 — h5.2.9.3410 · h5.3.0.3115 — h5.3.4.3500 · h6.0.0.3324 — h6.0.0.3397

Mitigating Controls

No mitigating controls mapped yet. The per-CVE control annotator has not reached this CVE.

References