NULL pointer dereference in Qnap Quts Hero

CVE-2025-66274

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 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

EPSS: 0.004 (29.6th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 4.9 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2025-66274?
CVE-2025-66274 is a medium-severity vulnerability in Qnap Quts Hero, classified under NULL Pointer Dereference. CVSS score: 4.9/10. Published 2026-02-11.
How severe is CVE-2025-66274?
Medium severity. CVSS v3 base score is 4.9 out of 10.