CVE-2026-9780

High

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.

SeverityHigh
CVSS8.8
Exploit probability—
ProductQuest Netvault Backup
PublishedJun 25, 2026
First seenJun 25, 2026

How to fix

Update
  • quest netvault_backup14.0.2 or later

Affected products

ProductAffected versionsFixed in
quest netvault_backupv < 14.0.214.0.2

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