Cyber Resilience

CVE-2025-66274

MediumUpdated

Published: 11 February 2026

Published
11 February 2026
Modified
09 June 2026
KEV Added
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Patch
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CVSS Score v4 5.1 CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:L/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 0.0014 34.7th percentile
Risk Priority 10 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2025-66274 is a medium-severity NULL Pointer Dereference (CWE-476) vulnerability in Qnap Quts Hero. Its CVSS base score is 5.1 (Medium).

Operationally, ranked at the 34.7th 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. If a remote attacker gains an administrator account, they can then exploit the vulnerability to launch a denial-of-service (DoS) attack. We have already fixed the…

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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 h5.3.2.3354 build 20251225 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
quts hero
h5.3.0.3115, h5.3.0.3145, h5.3.0.3192, h5.3.1.3250, h5.3.1.3292

Mitigating Controls

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

References