QTS, QuTS hero

published 2026-06-09 5 mo ago modified 2026-10-19 21 d ago also EUVD-2026-35350

cvss: 6.1; version 3.1, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 0.2%; EPSS 0.2% chance of exploitation in 30 days, percentile 8%
public exploits: 0; none known

A cross-site scripting (XSS) vulnerability has been reported to affect several QNAP operating system versions. The remote attackers can then exploit the vulnerability to bypass security mechanisms or read application data.

We have already fixed the vulnerability in the following versions: QTS 5.2.9.3492 build 20260507 and later QuTS hero h5.2.9.3499 build 20260514 and later QuTS hero h5.3.4.3500 build 20260520 and later QuTS hero h6.0.0.3500 build 20260520 and later

Patch / fix

fixed in 2

QNAP Systems Inc. QTS 5.2.9.3492 build 20260507
QNAP Systems Inc. QuTS hero h5.2.9.3499 build 20260514, h5.3.4.3500 build 20260520, h6.0.0.3500 build 20260520

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: total
Assessed: 5 mo ago (2026-06-09)

Exploit prediction

0.19% chance of exploitation in the next 30 days, higher than 8% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	4.0	6.3	CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U
CNA	4.0	6.3	CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/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
NVD	3.1	6.1	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Affected products

QNAP Systems Inc. QTS
QNAP Systems Inc. QuTS hero

Classification

Weakness

CWE-79 Improper Neutralization of Input During Web Page Generation

References

qnap.com /en/security-advisory/qsa-26-10

Sources

CVE List CVE-2026-41539
NVD CVE-2026-41539

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary