CVE-2025-66277 CRITICAL

CVE-2025-66277: QTS, QuTS hero

Vendor Qnap Systems Inc.
Product QTS
Weakness CWE-59
Published February 11, 2026
Last update February 26, 2026
View on NVD All CVEs

CVSS base score

9.2/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality —
Integrity —

CVSS vector

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

What the vulnerability does

01Description

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

Key dates

02Disclosure timeline

February 11, 2026 CVE published
February 26, 2026 Record updated