MediumGHSA-9965-vmph-33xxCVE-2025-56200

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

Published 30 Sept 2025 · Updated 10 Sept 2026

Affected package

Affected: <13.15.20
Fixed in: 13.15.20

Update to the fixed version for your release line, for example:npm install validator@13.15.20

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.

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References

Advisory data from OSV.dev (opens OSV.dev in a new tab), refreshed daily.