# CVE-2023-43804: `Cookie` HTTP header isn't stripped on cross-origin redirects

Source: https://junglewise.ai/threats/cve-2023-43804-cookie-http-header-isn-t-stripped-on-cross-origin-redirects  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2023-10-04  
License: CC BY 4.0 with a link back

CVE-2023-43804 · Severity: low · CVSS 3.1 · Published 2023-10-04

urllib3 is a user-friendly HTTP client library for Python. urllib3 doesn't treat the `Cookie` HTTP header special or provide any helpers for managing cookies over HTTP, that is the responsibility of the user. However, it is possible for a user to specify a `Cookie` header and unknowingly leak information via HTTP redirects to a different origin if that user doesn't disable redirects explicitly. This issue has been patched in urllib3 version 1.26.17 or 2.0.5.

Technologies: [urllib3 (PyPI)](https://junglewise.ai/threats/technologies/urllib3). Vendors: [PyPI](https://junglewise.ai/threats/vendors/pypi).

## Quick answers

**Is CVE-2023-43804 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2023-43804 being exploited in the wild.

**How severe is CVE-2023-43804?** Low severity, with a CVSS score of 3.1, published 4 October 2023.

**Which products and versions are affected?** urllib3 (PyPI) ECOSYSTEM:introduced=2.0.0,fixed=2.0.6, GIT:introduced=0,fixed=644124ecd0b6e417c527191f866daa05a5a2056d,fixed=01220354d389cd05474713f8c982d05c9b17aafb|ECOSYSTEM:introduced=2.0.0,fixed=2.0.6,introduced=0,fixed=1.26.17.

**Is there a fix for CVE-2023-43804?** Yes. urllib3 (PyPI): upgrade to 1.26.17, 2.0.6 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**Am I affected by CVE-2023-43804?** Check whether you run urllib3 (PyPI) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- urllib3 (PyPI): upgrade to 1.26.17, 2.0.6 or later

  ```sh
  pip install "urllib3>=2.0.6"
  ```


## Affected products

- urllib3 (PyPI) ECOSYSTEM:introduced=2.0.0,fixed=2.0.6, GIT:introduced=0,fixed=644124ecd0b6e417c527191f866daa05a5a2056d,fixed=01220354d389cd05474713f8c982d05c9b17aafb|ECOSYSTEM:introduced=2.0.0,fixed=2.0.6,introduced=0,fixed=1.26.17

## Identifiers

- CVE-2023-43804
- GHSA-v845-jxx5-vc9f
- PYSEC-2023-192

## Related threats

- [urllib3 HTTP client unbounded memory allocation in chunked transfer](https://junglewise.ai/threats/cve-2026-97689-urllib3-is-an-http-client-library-for-python-from-1-10-3-until-2)
- [urllib3 infinite loop in Deflate decoder](https://junglewise.ai/threats/cve-2026-97688-urllib3-is-an-http-client-library-for-python-from-2-6-2-until-2-8)
- [urllib3 HTTPS proxy TLS settings isolation](https://junglewise.ai/threats/cve-2026-97687-urllib3-is-an-http-client-library-for-python-from-1-26-0-until-2)
- [PYSEC-2026-1997 - urllib3 does not control redirects in browsers and Node.js](https://junglewise.ai/threats/cve-2025-50182-urllib3-does-not-control-redirects-in-browsers-and-node-js)
- [PYSEC-2026-1999 - urllib3 redirects are not disabled when retries are disabled on PoolManager instantiation](https://junglewise.ai/threats/cve-2025-50181-urllib3-redirects-are-not-disabled-when-retries-are-disabled-on)