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QtsOperating system · Qnap

CVE-2026-41539

MEDIUM · 6.1 CVSS v3.1 Published 2026-06-09
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
68/100
Remediation priority · Elevated
Remotely reachable No privileges

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

This is a cross-site scripting (XSS) vulnerability affecting multiple QNAP QTS and QuTS hero operating system versions. Remote attackers can exploit this vulnerability to bypass security mechanisms or read application data through malicious scripts injected into vulnerable input fields or parameters.

MitigationUpdate affected QNAP devices to the fixed versions (QTS 5.2.9.3492 build 20260507 or later, QuTS hero h5.2.9.3499/h5.3.4.3500/h6.0.0.3500 build 20260520 or later) to remediate this XSS vulnerability.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
QtsOperating system
Affected:= 5.2.0.2737= 5.2.0.2744= 5.2.0.2782= 5.2.0.2802= 5.2.0.2823= 5.2.0.2851= 5.2.0.2860= 5.2.1.2930= 5.2.2.2950= 5.2.3.3006= 5.2.4.3070= 5.2.4.3079
Quts HeroOperating system
Affected:= h5.2.0.2737= h5.2.0.2782= h5.2.0.2789= h5.2.0.2802= h5.2.0.2823= h5.2.0.2851= h5.2.0.2860= h5.2.1.2929= h5.2.1.2940= h5.2.2.2952= h5.2.3.3006= h5.2.4.3070

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
Required
Scope
Changed
Confidentiality
Low
Integrity
Low
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify the QNAP product type
    Log into the QNAP device and go to Control Panel > System > System Status, or check the login page/console for the product name (QTS or QuTS hero)
    Affected if Product is QTS or QuTS hero with web management interface enabled
  2. Check the firmware version in QTS
    In QTS, go to Control Panel > System > Firmware Update > Check for Update, or use the command: getsysinfo sysfirmware in the QNAP CLI
    Affected if Firmware version matches any of: 5.2.0.2737, 5.2.0.2744, 5.2.0.2782, 5.2.0.2802, 5.2.0.2823, 5.2.0.2851, 5.2.0.2860, 5.2.1.2930, 5.2.2.2950, 5.2.3.3006, 5.2.4.3070, or 5.2.4.3079
  3. Check the firmware version in QuTS hero
    In QuTS hero, go to Control Panel > System > Firmware Update > Check for Update, or use the command: getsysinfo sysfirmware in the QNAP CLI
    Affected if Firmware version matches any of: h5.2.0.2737, h5.2.0.2782, h5.2.0.2789, h5.2.0.2802, h5.2.0.2823, h5.2.0.2851, h5.2.0.2860, h5.2.1.2929, h5.2.1.2940, h5.2.2.2952, h5.2.3.3006, or h5.2.4.3070
  4. Verify the web management interface is accessible
    Attempt to access the QNAP device web interface via HTTPS on port 8080 or 443 (or configured port) from a browser
    Affected if Web interface is reachable and the device runs an affected firmware version

The device is affected if it runs QTS or QuTS hero with a firmware version matching any of the specific versions listed in the affected products, and the web management interface is enabled.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Update affected QNAP devices to the fixed versions (QTS 5.2.9.3492 build 20260507 or later, QuTS hero h5.2.9.3499/h5.3.4.3500/h6.0.0.3500 build 20260520 or later) to remediate this XSS vulnerability.

Recommended fix High confidence

QTS: 5.2.9.3492 build 20260507 or later; QuTS hero: h5.2.9.3499 build 20260514 or later (or h5.3.4.3500/h6.0.0.3500 or later)

  1. 1. Identify the QNAP product variant (QTS or QuTS hero) currently running on the device
  2. 2. Access the QNAP admin console and navigate to Control Panel > System > Firmware Update
  3. 3. Check the current firmware version under System > System Information
  4. 4. For QTS systems: Upgrade to QTS 5.2.9.3492 (build 20260507) or later version
  5. 5. For QuTS hero systems: Upgrade to QuTS hero h5.2.9.3499 (build 20260514), h5.3.4.3500 (build 20260520), or h6.0.0.3500 (build 20260520) or later
  6. 6. Verify the upgrade completed successfully and confirm the new version in System > System Information
Caveat Standard QNAP firmware upgrade precautions apply - ensure data backups are in place before performing firmware updates

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Qts Scoped from the published advisory
  • Consultation4.0 h
  • Implementation6.0 h
  • Testing3.0 h
  • Review / QA2.0 h
15.0 hours of engineering $2,690
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-41539 in production — separate from our analysis above.

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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