Is CVE-2026-44431 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-44431 being exploited in the wild.

How severe is CVE-2026-44431?

Medium severity, with a CVSS score of 5.3, published 13 May 2026.

Which products and versions are affected?

urllib3 (PyPI) >= 1.23, < 2.7.0, ECOSYSTEM:introduced=1.23,fixed=2.7.0.

Is there a fix for CVE-2026-44431?

Yes. urllib3 (PyPI): upgrade to 2.7.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-44431 attacked?

It is attacked over the network, in a software library.

Am I affected by CVE-2026-44431?

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.

CVE-2026-44431: urllib3 sensitive header leak in ProxyManager low-level redirects

Q: Is there a fix for CVE-2026-44431?

Yes. urllib3 (PyPI): upgrade to 2.7.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

Q: How is CVE-2026-44431 attacked?

It is attacked over the network, in a software library.

Q: Am I affected by CVE-2026-44431?

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.

CVE-2026-44431 · Severity: medium · CVSS 5.3 · Published 2026-05-13

urllib3 is a widely used Python library for making web requests. A security flaw exists where sensitive information, such as login credentials and session cookies, may be unintentionally sent to an untrusted third-party website during a redirect. This could allow an attacker to steal user sessions or authentication tokens if an application uses specific low-level functions of the library.

Technologies: urllib3 (PyPI). Vendors: PyPI.

Quick answers

Is CVE-2026-44431 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-44431 being exploited in the wild.
How severe is CVE-2026-44431?: Medium severity, with a CVSS score of 5.3, published 13 May 2026.
Which products and versions are affected?: urllib3 (PyPI) >= 1.23, < 2.7.0, ECOSYSTEM:introduced=1.23,fixed=2.7.0.
Is there a fix for CVE-2026-44431?: Yes. urllib3 (PyPI): upgrade to 2.7.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-44431 attacked?: It is attacked over the network, in a software library.
Am I affected by CVE-2026-44431?: 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 2.7.0 or later
```
pip install "urllib3>=2.7.0"
```

Technical details

An information exposure vulnerability exists in urllib3's low-level API. When using ProxyManager.connection_from_url().urlopen() with assert_same_host=False, the library fails to strip sensitive headers (Authorization, Cookie, and Proxy-Authorization) during cross-origin redirects. While the high-level request() API correctly handles these redirects by removing headers defined in Retry.DEFAULT_REMOVE_HEADERS_ON_REDIRECT, the low-level flow bypasses these protections. An attacker who can trigger a redirect to a malicious domain could capture these sensitive headers. The issue is resolved in version 2.7.0.

Affected products

urllib3 urllib3 >= 1.23, < 2.7.0

Identifiers

CVE-2026-44431
GHSA-qccp-gfcp-xxvc
PYSEC-2026-141

Timeline

2026-05-07: advisory: GitHub Security Advisory published
2026-05-13: disclosed: CVE published to NVD
2026-06-26: patched: Debian LTS security update released

References

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