CVE-2026-41539: CWE-79 in QNAP Systems Inc. QTS
CVE-2026-41539 is a high-severity cross-site scripting (XSS) vulnerability affecting multiple versions of QNAP's QTS operating system. This vulnerability allows remote attackers to bypass security mechanisms or read application data by exploiting the XSS flaw. The issue has been addressed and fixed in QTS 5. 2. 9. 3492 build 20260507 and later, as well as in several QuTS hero versions released in May 2026. The vulnerability has a CVSS 4. 0 base score of 8. 7, indicating a significant risk if unpatched. No known exploits are reported in the wild at this time.
AI Analysis
Technical Summary
CVE-2026-41539 is a cross-site scripting (CWE-79) vulnerability in QNAP Systems Inc.'s QTS operating system, allowing remote attackers to bypass security controls or access application data. It affects QTS version 5.2.0 and possibly other earlier versions. The vulnerability has been fixed in QTS 5.2.9.3492 build 20260507 and later, as well as in QuTS hero h5.2.9.3499, h5.3.4.3500, and h6.0.0.3500 builds released in May 2026. The CVSS 4.0 score is 8.7, reflecting network attack vector, low attack complexity, no privileges required, user interaction needed, and high impact on confidentiality, integrity, and availability.
Potential Impact
Successful exploitation of this XSS vulnerability can allow remote attackers to bypass security mechanisms or read sensitive application data, potentially leading to unauthorized actions or information disclosure. The high CVSS score indicates a serious impact on confidentiality, integrity, and availability of the affected systems. However, no known exploits have been reported in the wild so far.
Mitigation Recommendations
The vulnerability has been fixed in QTS 5.2.9.3492 build 20260507 and later versions, as well as in QuTS hero h5.2.9.3499, h5.3.4.3500, and h6.0.0.3500 builds. Users should upgrade their QNAP QTS or QuTS hero systems to these fixed versions to remediate the vulnerability. Patch status is confirmed by the vendor advisory embedded in the description. No additional mitigation steps are indicated.
CVE-2026-41539: CWE-79 in QNAP Systems Inc. QTS
Description
CVE-2026-41539 is a high-severity cross-site scripting (XSS) vulnerability affecting multiple versions of QNAP's QTS operating system. This vulnerability allows remote attackers to bypass security mechanisms or read application data by exploiting the XSS flaw. The issue has been addressed and fixed in QTS 5. 2. 9. 3492 build 20260507 and later, as well as in several QuTS hero versions released in May 2026. The vulnerability has a CVSS 4. 0 base score of 8. 7, indicating a significant risk if unpatched. No known exploits are reported in the wild at this time.
CVSS v4.0
Score 8.7high
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-41539 is a cross-site scripting (CWE-79) vulnerability in QNAP Systems Inc.'s QTS operating system, allowing remote attackers to bypass security controls or access application data. It affects QTS version 5.2.0 and possibly other earlier versions. The vulnerability has been fixed in QTS 5.2.9.3492 build 20260507 and later, as well as in QuTS hero h5.2.9.3499, h5.3.4.3500, and h6.0.0.3500 builds released in May 2026. The CVSS 4.0 score is 8.7, reflecting network attack vector, low attack complexity, no privileges required, user interaction needed, and high impact on confidentiality, integrity, and availability.
Potential Impact
Successful exploitation of this XSS vulnerability can allow remote attackers to bypass security mechanisms or read sensitive application data, potentially leading to unauthorized actions or information disclosure. The high CVSS score indicates a serious impact on confidentiality, integrity, and availability of the affected systems. However, no known exploits have been reported in the wild so far.
Mitigation Recommendations
The vulnerability has been fixed in QTS 5.2.9.3492 build 20260507 and later versions, as well as in QuTS hero h5.2.9.3499, h5.3.4.3500, and h6.0.0.3500 builds. Users should upgrade their QNAP QTS or QuTS hero systems to these fixed versions to remediate the vulnerability. Patch status is confirmed by the vendor advisory embedded in the description. No additional mitigation steps are indicated.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- qnap
- Date Reserved
- 2026-04-21T03:07:17.287Z
- Cvss Version
- 4.0
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a27adb3e29bf47b504f94c2
Added to database: 6/9/2026, 6:07:47 AM
Last enriched: 6/9/2026, 6:18:37 AM
Last updated: 6/9/2026, 7:58:19 AM
Views: 6
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