CVE-2025-66281 QTS, QuTS hero
Remote attackers can cause a denial-of-service condition in QNAP QTS and QuTS hero operating systems via a NULL pointer dereference.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2025-66281?
CVE-2025-66281 is a medium-severity vulnerability in Qnap Qts, published on 10 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
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: CWE-476
Which versions are affected by CVE-2025-66281?
It affects 2 products.
Products include Qnap Qts, Qnap Quts Hero.
How do I fix CVE-2025-66281?
No fix has been published for CVE-2025-66281 yet. Limit exposure of the affected software until one is available.
Is CVE-2025-66281 being exploited?
There is no known exploitation of CVE-2025-66281 in the wild and no public exploit code.
Other vulnerabilities in Qnap Qts
Sources
Also known as GHSA-hjv6-9pr5-j6w8.