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 version: QuTS hero h5.3.2.3354 build 20251225 and later
Conclusion & alert: CVE-2025-66274 is rated Low Risk (16.8/100): CVSS Low severity, with low exploitation likelihood (EPSS 0.14%). Mandatory action: Low composite risk—no urgent action required; patch on your normal maintenance cycle and revisit priority if CVSS or EPSS increases.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2026-02-12 | — | 0.14% | — |
Full EPSS history (1 record total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 1.2 | 4.0 | LOW |
|
— | — | [email protected] |
| 4.9 | 3.1 | MEDIUM |
|
1.2 | 3.6 | [email protected] |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| qnap | quts_hero | h5.3.0.3115 | cpe:2.3:o:qnap:quts_hero:h5.3.0.3115:build_20250430:*:*:*:*:*:* |
| qnap | quts_hero | h5.3.0.3145 | cpe:2.3:o:qnap:quts_hero:h5.3.0.3145:build_20250530:*:*:*:*:*:* |
| qnap | quts_hero | h5.3.0.3192 | cpe:2.3:o:qnap:quts_hero:h5.3.0.3192:build_20250716:*:*:*:*:*:* |
| qnap | quts_hero | h5.3.1.3250 | cpe:2.3:o:qnap:quts_hero:h5.3.1.3250:build_20250912:*:*:*:*:*:* |
| qnap | quts_hero | h5.3.1.3292 | cpe:2.3:o:qnap:quts_hero:h5.3.1.3292:build_20251024:*:*:*:*:*:* |
| URL | Tags |
|---|---|
| https://www.qnap.com/en/security-advisory/qsa-26-08 | Vendor Advisory |