What’s Vulnerable › Vulnerabilities

CVE-2025-50182: urllib3 does not control redirects in browsers and Node.js

• Severity: medium (CVSS 6.1 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.6% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2025-06-19 · updated 2026-06-17
• Weakness: CWE-601

Description

urllib3 is a user-friendly HTTP client library for Python. Starting in version 2.2.0 and prior to 2.5.0, urllib3 does not control redirects in browsers and Node.js. urllib3 supports being used in a Pyodide runtime utilizing the JavaScript Fetch API or falling back on XMLHttpRequest. This means Python libraries can be used to make HTTP requests from a browser or Node.js. Additionally, urllib3 provides a mechanism to control redirects, but the retries and redirect parameters are ignored with Pyodide; the runtime itself determines redirect behavior. This issue has been patched in version 2.5.0.

Affected products

• urllib3: from 2.2.0 before 2.5.0 — fixed in 2.5.0

How to fix

Upgrade to a fixed version: urllib3 2.5.0. Check the vendor advisory for mitigations.

References

• https://github.com/urllib3/urllib3/commit/7eb4a2aafe49a279c29b6d1f0ed0f42e9736194f
• https://github.com/urllib3/urllib3/releases/tag/2.5.0
• https://github.com/urllib3/urllib3/security/advisories/GHSA-48p4-8xcf-vxj5

Get alerted when CVE-2025-50182 or the next vulnerability affects your stack