CVE-2025-56200: Validator Validator.js Has A URL Validation Vulnerability

MODERATE
Advisory Identifier: GHSA-9965-vmph-33xx
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CVSS 6.1
CWE-79
Published
Advisory Summary

CVE-2025-56200 is a MODERATE (CVSS 6.1) validator.js has a url validation vulnerability (CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')) affecting Validator libraries in the npm ecosystem. The issue involves validator.js has a url validation bypass vulnerability in its isurl function. Remediation is available by upgrading affected packages to version 13.15.20.

CVE-2025-56200 at a Glance

CVE Identifier CVE-2025-56200
GHSA Identifier GHSA-9965-vmph-33xx
Severity MODERATE
CVSS v3.1 Base Score 6.1
CWE Classification CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Affected Product Validator
Package Ecosystem npm
Published Date
Last Updated

Security Impact

CVSS: 6.1

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction Required (UI:R)
Scope Changed (S:C)
Confidentiality Low (C:L)
Integrity Low (I:L)
Availability None (A:N)

How to Fix CVE-2025-56200

To remediate this vulnerability, upgrade all affected Validator dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

validator fixed: 13.15.20 
npm install validator@13.15.20
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

npm ls validator

How to Check if You Are Affected

To determine whether your Node.js application is affected by CVE-2025-56200, inspect your project dependencies using npm:

npm ls validator

Analyze the terminal output to locate any version of Validator in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 13.15.20), your application is affected.

Note: The npm ls validator command inspects dependencies declared in your package.json and lockfile; it does not perform automated runtime dynamic scanning.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting'), where the product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. In Validator, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

A URL validation bypass vulnerability exists in validator.js prior to version 13.15.20. The isURL() function uses '://' as a delimiter to parse protocols, while browsers use ':' as the delimiter. This parsing difference allows attackers to bypass protocol and domain validation by crafting URLs leading to XSS and Open Redirect attacks.

CVE-2025-56200 Affected Validator Versions

1 component(s)
Fixed Versions:
13.15.20
Product / Package Ecosystem Affected Versions Fixed Version
validator
npm/validator
npm
< 13.15.20
13.15.20

References

NVD — CVE-2025-56200 NVD
https://nvd.nist.gov/vuln/detail/CVE-2025-56200
Validator Source Repository REPOSITORY
https://github.com/validatorjs/validator.js/issues/2600
Validator Source Repository REPOSITORY
https://github.com/validatorjs/validator.js/pull/2608
Security Fix Commit FIX COMMIT
https://github.com/validatorjs/validator.js/commit/cbef5088f02d36caf978f378bb845fe49bdc0809
Validator Source Repository REPOSITORY
https://gist.github.com/junan-98/27ae092aa40e2a057d41a0f95148f666
Validator Source Repository REPOSITORY
https://gist.github.com/junan-98/a93130505b258b9e4ec9f393e7533596
Validator Source Repository REPOSITORY
https://github.com/validatorjs/validator.js
Validator Release RELEASE
https://github.com/validatorjs/validator.js/releases/tag/13.15.20
Validator Security Information SECURITY
http://validatorjs.com

Frequently Asked Questions

What is CVE-2025-56200?
CVE-2025-56200 is a security vulnerability in Validator involving validator.js has a URL validation bypass vulnerability in its isURL function under CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting').
Which Validator versions are affected?
Affected versions include releases prior to 13.15.20 across affected packages: validator.
What version fixes CVE-2025-56200?
Upgrading to 13.15.20 (or the latest patched release for your respective branch) resolves the vulnerability.
Is validator affected?
Yes, validator is affected in releases prior to 13.15.20. Upgrade your dependency to 13.15.20 or later.
What is the CVSS score of CVE-2025-56200?
CVE-2025-56200 has a CVSS v3.1 base score of 6.1 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.
What CWE is associated with CVE-2025-56200?
CVE-2025-56200 is classified under CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') (The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.).
How can I check npm dependencies for CVE-2025-56200?
Run the dependency tree command: 'npm ls validator'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-9965-vmph-33xx",
  "modified" : "2025-10-27T12:53:01Z",
  "published" : "2025-09-30T18:30:25Z",
  "aliases" : [ "CVE-2025-56200" ],
  "summary" : "validator.js has a URL validation bypass vulnerability in its isURL function",
  "details" : "A URL validation bypass vulnerability exists in validator.js prior to version 13.15.20. The isURL() function uses '://' as a delimiter to parse protocols, while browsers use ':' as the delimiter. This parsing difference allows attackers to bypass protocol and domain validation by crafting URLs leading to XSS and Open Redirect attacks.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "validator"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "13.15.20"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2025-56200"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/validatorjs/validator.js/issues/2600"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/validatorjs/validator.js/pull/2608"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/validatorjs/validator.js/commit/cbef5088f02d36caf978f378bb845fe49bdc0809"
  }, {
    "type" : "WEB",
    "url" : "https://gist.github.com/junan-98/27ae092aa40e2a057d41a0f95148f666"
  }, {
    "type" : "WEB",
    "url" : "https://gist.github.com/junan-98/a93130505b258b9e4ec9f393e7533596"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/validatorjs/validator.js"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/validatorjs/validator.js/releases/tag/13.15.20"
  }, {
    "type" : "WEB",
    "url" : "http://validatorjs.com"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-79" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2025-10-13T20:08:58Z",
    "nvd_published_at" : "2025-09-30T18:15:50Z"
  }
}