CVE-2026-41539 QTS, QuTS hero

What is CVE-2026-41539?

CVE-2026-41539 is a medium-severity cross-site scripting vulnerability in Qnap Qts, published on 9 Jun 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

Official description

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

Weakness: CWE-79

Which versions are affected by CVE-2026-41539?

It affects 2 products.

Products include Qnap Qts, Qnap Quts Hero.

How do I fix CVE-2026-41539?

No fix has been published for CVE-2026-41539 yet. Limit exposure of the affected software until one is available.

Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.

Is CVE-2026-41539 being exploited?

There is no known exploitation of CVE-2026-41539 in the wild and no public exploit code.

Other vulnerabilities in Qnap Qts

• CVE-2020-2509 QNAP Network-Attached Storage (NAS) Command Injection Exploited Critical 9.8
• CVE-2018-19949 QNAP NAS File Station Command Injection Exploited Critical 9.8
• CVE-2019-7193 QNAP QTS Improper Input Validation Exploited Critical 9.8
• CVE-2018-19943 QNAP NAS File Station Cross-Site Scripting Exploited High 8.0
• CVE-2018-19953 QNAP NAS File Station Cross-Site Scripting Exploited Medium 6.1

All Qnap Qts vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-hc5c-8r54-29r3.