QNAP QTS Null Ptr Deref DoS (pre 5.2.9.3410, fixed in 5.2.9.3410)
CVE-2025-66281 Published on June 10, 2026
QTS, QuTS hero
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 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
Weakness Type
NULL Pointer Dereference
A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. NULL pointer dereference issues can occur through a number of flaws, including race conditions, and simple programming omissions.
Products Associated with CVE-2025-66281
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Affected Versions
QNAP Systems Inc. QTS:- Version 5.2.0 and below 5.2.9.3410 build 20260214 is affected.
- Version h5.2.0 and below h5.2.9.3410 build 20260214 is affected.
- Version h5.3.0 and below h5.3.4.3500 build 20260520 is affected.
- Version ? and below h6.0.0.3397 build 20260206 is affected.