How severe is CVE-2026-41539?

CVE-2026-41539 has a CVSS 3.x base score of 6.1, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2026-41539 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (9th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-41539?

CVE-2026-41539 primarily affects Qnap Qts. In total, 56 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2026-41539?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-41539 have an EU (EUVD) identifier?

Yes. CVE-2026-41539 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-35350.

When was CVE-2026-41539 published?

CVE-2026-41539 was published on 2026-06-09 and last updated on 2026-06-30.

CVE-2026-41539

CVE-2026-41539 is a medium-severity vulnerability in Qnap Qts with a CVSS 3.x base score of 6.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-79.

Key facts

Severity: Medium (CVSS 3.x base score 6.1)
CVSS v4: 6.3
EPSS exploit prediction: 0% (9th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-35350
Weakness: CWE-79
Affected product: Qnap Qts
Published: 2026-06-09
Last modified: 2026-06-30

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

Frequently asked questions

What is CVE-2026-41539?: 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
How severe is CVE-2026-41539?: CVE-2026-41539 has a CVSS 3.x base score of 6.1, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2026-41539 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (9th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-41539?: CVE-2026-41539 primarily affects Qnap Qts. In total, 56 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2026-41539?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-41539 have an EU (EUVD) identifier?: Yes. CVE-2026-41539 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-35350.
When was CVE-2026-41539 published?: CVE-2026-41539 was published on 2026-06-09 and last updated on 2026-06-30.

References

https://www.qnap.com/en/security-advisory/qsa-26-10

EU advisories (EUVD)

https://www.qnap.com/en/security-advisory/qsa-26-31

Affected products (56)

cpe:2.3:o:qnap:qts:5.2.0.2737:build_20240417:*:*:*:*:*:*
cpe:2.3:o:qnap:qts:5.2.0.2744:build_20240424:*:*:*:*:*:*
cpe:2.3:o:qnap:qts:5.2.0.2782:build_20240601:*:*:*:*:*:*
cpe:2.3:o:qnap:qts:5.2.0.2802:build_20240620:*:*:*:*:*:*
cpe:2.3:o:qnap:qts:5.2.0.2823:build_20240711:*:*:*:*:*:*
cpe:2.3:o:qnap:qts:5.2.0.2851:build_20240808:*:*:*:*:*:*
cpe:2.3:o:qnap:qts:5.2.0.2860:build_20240817:*:*:*:*:*:*
cpe:2.3:o:qnap:qts:5.2.1.2930:build_20241025:*:*:*:*:*:*
cpe:2.3:o:qnap:qts:5.2.2.2950:build_20241114:*:*:*:*:*:*
cpe:2.3:o:qnap:qts:5.2.3.3006:build_20250108:*:*:*:*:*:*
cpe:2.3:o:qnap:qts:5.2.4.3070:build_20250312:*:*:*:*:*:*
cpe:2.3:o:qnap:qts:5.2.4.3079:build_20250321:*:*:*:*:*:*
cpe:2.3:o:qnap:qts:5.2.4.3092:build_20250403:*:*:*:*:*:*
cpe:2.3:o:qnap:qts:5.2.5.3145:build_20250526:*:*:*:*:*:*
cpe:2.3:o:qnap:qts:5.2.6.3195:build_20250715:*:*:*:*:*:*
cpe:2.3:o:qnap:qts:5.2.6.3229:build_20250818:*:*:*:*:*:*
cpe:2.3:o:qnap:qts:5.2.7.3256:build_20250913:*:*:*:*:*:*
cpe:2.3:o:qnap:qts:5.2.7.3297:build_20251024:*:*:*:*:*:*
cpe:2.3:o:qnap:qts:5.2.8.3332:build_20251128:*:*:*:*:*:*
cpe:2.3:o:qnap:qts:5.2.8.3350:build_20251216:*:*:*:*:*:*
cpe:2.3:o:qnap:qts:5.2.8.3359:build_20251225:*:*:*:*:*:*
cpe:2.3:o:qnap:qts:5.2.9.3410:build_20260214:*:*:*:*:*:*
cpe:2.3:o:qnap:qts:5.2.9.3451:build_20260327:*:*:*:*:*:*
cpe:2.3:o:qnap:quts_hero:h5.2.0.2737:build_20240417:*:*:*:*:*:*
cpe:2.3:o:qnap:quts_hero:h5.2.0.2782:build_20240601:*:*:*:*:*:*
cpe:2.3:o:qnap:quts_hero:h5.2.0.2789:build_20240607:*:*:*:*:*:*
cpe:2.3:o:qnap:quts_hero:h5.2.0.2802:build_20240620:*:*:*:*:*:*
cpe:2.3:o:qnap:quts_hero:h5.2.0.2823:build_20240711:*:*:*:*:*:*
cpe:2.3:o:qnap:quts_hero:h5.2.0.2851:build_20240808:*:*:*:*:*:*
cpe:2.3:o:qnap:quts_hero:h5.2.0.2860:build_20240817:*:*:*:*:*:*
cpe:2.3:o:qnap:quts_hero:h5.2.1.2929:build_20241025:*:*:*:*:*:*
cpe:2.3:o:qnap:quts_hero:h5.2.1.2940:build_20241105:*:*:*:*:*:*
cpe:2.3:o:qnap:quts_hero:h5.2.2.2952:build_20241116:*:*:*:*:*:*
cpe:2.3:o:qnap:quts_hero:h5.2.3.3006:build_20250108:*:*:*:*:*:*
cpe:2.3:o:qnap:quts_hero:h5.2.4.3070:build_20250312:*:*:*:*:*:*
cpe:2.3:o:qnap:quts_hero:h5.2.4.3079:build_20250321:*:*:*:*:*:*
cpe:2.3:o:qnap:quts_hero:h5.2.5.3138:build_20250519:*:*:*:*:*:*
cpe:2.3:o:qnap:quts_hero:h5.2.6.3195:build_20250715:*:*:*:*:*:*
cpe:2.3:o:qnap:quts_hero:h5.2.7.3256:build_20250913:*:*:*:*:*:*
cpe:2.3:o:qnap:quts_hero:h5.2.7.3297:build_20251024:*:*:*:*:*:*

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