CVE-2025-66274
Modified Modified - Updated After Analysis
NULL Pointer Dereference in QNAP OS Allows Admin-Triggered DoS

Publication date: 2026-02-11

Last updated on: 2026-06-09

Assigner: QNAP Systems, Inc.

Description
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
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Meta Information
Published
2026-02-11
Last Modified
2026-06-09
Generated
2026-06-16
AI Q&A
2026-02-11
EPSS Evaluated
2026-06-15
NVD
CVE-2025-66274
Affected Vendors & Products
Showing 5 associated CPEs
Vendor Product Version / Range
qnap quts_hero h5.3.0.3115
qnap quts_hero h5.3.0.3145
qnap quts_hero h5.3.0.3192
qnap quts_hero h5.3.1.3250
qnap quts_hero h5.3.1.3292
Helpful Resources
Exploitability
CWE
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KEV
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CWE ID Description
CWE-476 The product dereferences a pointer that it expects to be valid but is NULL.
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Executive Summary

This vulnerability is a NULL pointer dereference issue affecting several versions of the QNAP operating system. It occurs when a remote attacker who has already obtained an administrator account exploits this flaw to cause the system to crash or become unavailable, resulting in a denial-of-service (DoS) attack.

Impact Analysis

If exploited, this vulnerability can cause a denial-of-service condition on affected QNAP devices. This means that the system could become unresponsive or crash, disrupting normal operations and potentially causing downtime.

Compliance Impact

I don't know

Detection Guidance

I don't know

Mitigation Strategies

To mitigate this vulnerability, you should upgrade your QNAP operating system to QuTS hero version h5.3.2.3354 build 20251225 or later, where the issue has been fixed.

Additionally, restrict administrator account access to trusted users only, as exploitation requires an attacker to have administrator privileges.

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