Quick answer
Direct answer
Risk scores
| CVSS metric | What it means |
|---|---|
| Attack vector (AV:N) | Network: reachable remotely |
| Attack complexity (AC:L) | Low complexity |
| Attack requirements (AT:N) | No attack requirements |
| Privileges required (PR:H) | High privileges required |
| User interaction (UI:N) | No user interaction |
| Confidentiality (VC:H) | High confidentiality impact |
| Integrity (VI:H) | High integrity impact |
| Availability (VA:H) | High availability impact |
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/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
About Qnap Qts
CVE-2025-66273 affects Qnap Qts, a product from Qnap. Before acting, confirm where Qnap Qts runs in your estate, who owns it and whether it is reachable from the internet, because exposure decides real risk more than the score alone.
What the flaw is
In plain terms: A command injection 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 execute arbitrary commands. 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
The weakness class is OS Command Injection. Untrusted input is passed to the operating system shell, letting an attacker run commands.
Based on its CVSS vector, the flaw can be reached over the network, needs some level of access, and needs no user interaction. Apply the vendor fix and confirm exposure on internet facing and business critical assets first.
Affected versions and timeline
| Field | Detail |
|---|---|
| Product | Qnap Qts |
| Affected versions | Qts from 5.2.0.2737 before 5.2.9.3410; Quts Hero from h5.2.0.2737 before h5.2.9.3410; Quts Hero from h5.3.0.3115 before h5.3.4.3500; Quts Hero from h6.0.0.3324 before h6.0.0.3397 |
| Published | Jun 10, 2026 |
| Last modified | Jul 23, 2026 |
| Added to CISA KEV | Not listed |
| Assigning CNA | security@qnapsecurity.com.tw |
How to detect it
- Inventory every instance of Qnap Qts and record the running version against the affected range above.
- Check external attack surface scans for internet facing instances of the component.
- Review logs on affected systems for unusual requests, errors or new processes around the vulnerable function.
- Confirm with an authenticated vulnerability scan once your scanner has a check for this CVE.
How to fix it
- Apply the fixed version of Qnap Qts named in the vendor advisory.
- If patching must wait, restrict network access to the affected service and put it behind authentication or a web application firewall rule.
- Rescan after the change to prove the exposure is gone, then close the ticket.
CTEM action plan
| CTEM stage | What to do for this CVE |
|---|---|
| Scope | Add every business service that depends on Qnap Qts to the current CTEM cycle. |
| Discover | Find all instances, including shadow and cloud deployments, and record versions and exposure. |
| Prioritize | Rank using EPSS and CVSS together with asset exposure and business impact. |
| Validate | Confirm the flaw is reachable and exploitable in your environment and that compensating controls work. |
| Mobilize | Assign the fix to the asset owner with a due date matched to the priority, then verify closure. |
CWE References
- CWE-78: OS Command Injection More CVEs with this weakness
Technical References
Frequently asked questions
Related CVEs
A command injection 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 execute arbitrary commands. 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 h6.0.0.3459 build 20260409 and later
A command injection 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 execute arbitrary commands. 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
QuTS hero is not affected. We have already fixed the vulnerability in the following version: QTS 5.2.7.3256 build 20250913 and later
An authorization bypass through user-controlled key vulnerability has been reported to affect QuMagie. The remote attackers can then exploit the vulnerability to gain unintended privileges. We have already fixed the vulnerability in the following version: QuMagie 2.9.1 and later
A missing authentication for critical function vulnerability has been reported to affect QVR Pro. The remote attackers can then exploit the vulnerability to gain access to the system. We have already fixed the vulnerability in the following version: QVR Pro 2.7.4.14 and later
A command injection vulnerability has been reported to affect QuNetSwitch. The remote attackers can then exploit the vulnerability to execute arbitrary commands. We have already fixed the vulnerability in the following version: QuNetSwitch 2.0.4.0415 and later
Earn your free CTEM certification.
Learn to scope, prioritize, validate and mobilize fixes for CVEs like CVE-2025-66273 with a free CTEM certification.
Beginner / Practitioner / Program Leader
Explore certifications