CVE-2025-66279
QNAP OS command injection allows arbitrary commands with admin auth.
Is CVE-2025-66279 being exploited?
Not confirmed. CVE-2025-66279 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 1.1% probability of exploitation in the next 30 days.
How severe is CVE-2025-66279?
CVE-2025-66279 is rated High with a CVSS score of 8.6. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2025-66279?
Yes. A fix has been recorded for CVE-2025-66279. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2025-66279 affect?
CVE-2025-66279 affects 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. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2025-66279?
Update to fixed QTS/QuTS builds
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Remote attacker with admin rights can execute arbitrary OS commands on affected QNAP NAS.
Patch when possible
- affected>= 5.2.0 and < 5.2.9.3410 build 20260214
- affected>= h5.2.0 and < h5.2.9.3410 build 20260214
- affected>= h5.3.0 and < h5.3.4.3500 build 20260520
- affected>= ? and < h6.0.0.3397 build 20260206
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.