XSS Filter Bypass via Encoded URL in validator
Versions of validator prior to 2.0.0 contained an xss filter method that is affected by several filter bypasses. This may result in a cross-site scripting vulnerability.
Proof of Concept
The xss() function removes the word "javascript" when contained inside an attribute.
However, it does not properly handle cases where characters have been hex-encoded.
As a result, it is possible to build an input that bypasses the filter but which the browser will accept as valid JavaScript.
For example:
<a href="javascript:...">abc</a>
will render as:
<a href="javascript:...">abc</a>
Recommendation
The package author has decided to remove the xss filter functionality in the latest version of this module. If this feature is not currently being used, you are not affected by the vulnerability. If it is being used, updating to the latest version of the module will break your application.
In order for affected users to mitigate this vulnerability, it is necessary to use an alternative package that provides similar functionality.
Affected software
Click a technology to see all vulnerabilities affecting it.
| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| npm package | validator | < 2.0.0 | 2.0.0 |
References
- https://nvd.nist.gov/vuln/detail/CVE-2014-9772
- https://github.com/chriso/validator.js/issues/181
- https://github.com/advisories/GHSA-79mx-88w7-8f7q
- https://github.com/chriso/validator.js
- https://www.npmjs.com/advisories/43
- http://www.openwall.com/lists/oss-security/2016/04/20/11
- http://www.securityfocus.com/bid/97102
- CVSS vector
CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N- Weakness (CWE)
CWE-79- Platform
- npm
- Package
validator- Disclosed
- 06.11.2018
- Updated
- 11.10.2026 10:22
Sources and licenses
OSV / GitHub Advisory Database - GHSA-79mx-88w7-8f7q - CC BY 4.0
Vulnerability history: validator
All published vulnerabilities of this package (npm package), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 10
- First → latest
- 10.2017 11.2025
- Without a fix
- 0
- Exploited in attacks
- 0
Severity breakdown
- High 2
- Medium 8
Disclosures per year
- 2017: 4
- 2018: 1
- 2019: 0
- 2020: 1
- 2021: 2
- 2022: 0
- 2023: 0
- 2024: 0
- 2025: 2
- 2026: 0
-
XSS Filter Bypass via Encoded URL in validator this entry
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