CVE-2026-41539Network attack vector

Administrator session disclosure via DOM-based XSS

Published Jun 9, 2026 · Updated Jun 9, 2026

DOM-based XSS in QNAP QTS and QuTS hero allows remote attackers to obtain administrator session information through a crafted webpage. QNAP identifies the flaw as DOM-based XSS but has not disclosed the affected client-side component or the unsafe DOM operation on attacker-controlled input. Exploitation requires an authenticated administrator to visit the crafted page, limiting the reported consequence to exposure of sensitive session information.

CVSS severity6.1
Medium
EPSS probability0.19%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

DOM-based XSS in QNAP QTS and QuTS hero allows remote attackers to obtain administrator session information through a crafted webpage. QNAP identifies the flaw as DOM-based XSS but has not disclosed the affected client-side component or the unsafe DOM operation on attacker-controlled input. Exploitation requires an authenticated administrator to visit the crafted page, limiting the reported consequence to exposure of sensitive session information.

The record

CVE
CVE-2026-41539
Published
Jun 9, 2026
Updated
Jun 9, 2026
Vendor
Linn Products Limited
Product
QuTS hero
Classifications
CWE-79, T1539
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 9, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 9, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=h5.2.0 <h5.2.9.3499 build 20260514
  2. Affected versionversion=h5.3.0 <h5.3.4.3500 build 20260520
  3. Affected versionversion=? <h6.0.0.3500 build 20260520

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Linn Products Limited · QuTS heroversion=h5.2.0 <h5.2.9.3499 build 20260514; version=h5.3.0 <h5.3.4.3500 build 20260520; version=? <h6.0.0.3500 build 20260520
Linn Products Limited · QTSversion=5.2.0 <5.2.9.3492 build 20260507

Published CVSS scores

6.1NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
6.3QNAP Systems, Inc.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

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1539Steal Web Session Cookie

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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