Vulnerability library
Security checkOctober 27, 2025

validator.js has a URL validation bypass vulnerability in its isURL function

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Medium severitynpmvalidator

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Description

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.

Recommendation

Update the validator package to the latest compatible version. Followings are version details:

  • Affected version(s): < 13.15.20
  • Patched version(s): 13.15.20

References

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Related Issues

See something that needs correcting? Let us knowUpdated October 27, 2025