# CVE-2025-66277

## Summary

- **CVE ID:** CVE-2025-66277
- **Severity:** CRITICAL
- **CVSS Score:** 9.2 (CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N)
- **CWE:** CWE-59
- **Published:** Feb 11, 2026
- **Last Modified:** Mar 13, 2026

## Description

A link following vulnerability has been reported to affect several QNAP operating system versions. The remote attackers can then exploit the vulnerability to traverse the file system to unintended locations.

We have already fixed the vulnerability in the following versions:
QTS 5.2.8.3350 build 20251216 and later
QuTS hero h5.3.2.3354 build 20251225 and later
QuTS hero h5.2.8.3350 build 20251216 and later

## Affected Products

- QNAP Systems Inc. — QTS (5.2.x)
- QNAP Systems Inc. — QuTS hero (h5.3.x)
- QNAP Systems Inc. — QuTS hero (h5.2.x)

## References

- [CNA](https://www.qnap.com/en/security-advisory/qsa-26-05)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.63%
- **EPSS Percentile:** 48.3

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-10._