CVE-2026-9780
Quest NetVault Backup addclient3 Cross-Site Scripting Authentication Bypass Vulnerability
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.
INFO
Published Date :
June 25, 2026, 12:17 a.m.
Last Modified :
June 26, 2026, 2:04 a.m.
Remotely Exploit :
No
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.0 | HIGH | 99f1926a-a320-47d8-bbb5-42feb611262e | ||||
| CVSS 3.0 | HIGH | [email protected] |
Solution
- Update Quest NetVault Backup to the latest version.
- Apply any available security patches from the vendor.
- Review access controls and authentication mechanisms.
- Restrict access to the addclient3 webpage.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-9780.
| URL | Resource |
|---|---|
| https://support.quest.com/technical-documents/netvault/14.0.2/release-notes#TOPIC-2338529 | Release Notes |
| https://www.zerodayinitiative.com/advisories/ZDI-26-369/ | Vendor Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-9780 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-9780
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-9780 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-9780 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Jun. 26, 2026
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:a:quest:netvault_backup:*:*:*:*:*:*:*:* versions up to (excluding) 14.0.2 Added Reference Type Zero Day Initiative: https://support.quest.com/technical-documents/netvault/14.0.2/release-notes#TOPIC-2338529 Types: Release Notes Added Reference Type Zero Day Initiative: https://www.zerodayinitiative.com/advisories/ZDI-26-369/ Types: Vendor Advisory -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jun. 25, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-9780', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-06-25T12:47:12.693151Z'} -
New CVE Received by [email protected]
Jun. 25, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'Quest', 'product': 'NetVault Backup', 'versions': [{'status': 'affected', 'version': '14.0.1.7'}], 'defaultStatus': 'unknown'}] 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. Added CVSS V3 AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H Added CWE CWE-79 Added Reference https://support.quest.com/technical-documents/netvault/14.0.2/release-notes#TOPIC-2338529 Added Reference https://www.zerodayinitiative.com/advisories/ZDI-26-369/