Quest NetVault Backup addclient3 Cross-Site Scripting Authentication Bypass Vulnerability. This vulnerability allows remote attackers to bypass authentication on affected installations of Quest NetVault Backup. User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious file. The specific flaw exists within the addclient3 webpage. The issue results from the lack of proper validation of user-supplied data, which can lead to the injection of an arbitrary script. An attacker can leverage this in conjunction with other vulnerabilities to execute arbitrary code in the context of SYSTEM. Was ZDI-CAN-27666.

Metrics

No CVSS v4.0

No CVSS v3.1

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Unchanged

Confidentiality Impact High

Integrity Impact High

Availability Impact High

User Interaction Required

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Key SSVC decision points have not yet been added.

Affected Vendors & Products

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Vendors Products
References
Link Providers
https://support.quest.com/technical-documents/netvault/14.0.2/release-notes#TOPIC-2338529 cve-icon
https://www.zerodayinitiative.com/advisories/ZDI-26-369/ cve-icon
History

Wed, 24 Jun 2026 23:45:00 +0000

Type Values Removed Values Added
Description Quest NetVault Backup addclient3 Cross-Site Scripting Authentication Bypass Vulnerability. This vulnerability allows remote attackers to bypass authentication on affected installations of Quest NetVault Backup. User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious file. The specific flaw exists within the addclient3 webpage. The issue results from the lack of proper validation of user-supplied data, which can lead to the injection of an arbitrary script. An attacker can leverage this in conjunction with other vulnerabilities to execute arbitrary code in the context of SYSTEM. Was ZDI-CAN-27666.
Title Quest NetVault Backup addclient3 Cross-Site Scripting Authentication Bypass Vulnerability
Weaknesses CWE-79
References
Metrics cvssV3_0

{'score': 8.8, 'vector': 'CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H'}
cve-icon MITRE

Status: PUBLISHED

Assigner: zdi

Published:

Updated: 2026-06-24T23:13:55.522Z

Reserved: 2026-05-27T22:27:43.798Z

Link: CVE-2026-9780

cve-icon Vulnrichment

No data.

cve-icon NVD

No data.

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-06-25T00:45:05Z