What is CVE-2026-44431?

CVE-2026-44431 is a medium-severity vulnerability in Python Urllib3, classified under Information Disclosure. CVSS score: 5.3/10. Published 2026-05-13.

How severe is CVE-2026-44431?

Medium severity. CVSS v3 base score is 5.3 out of 10.

Information disclosure in Python Urllib3

CVE-2026-44431

urllib3 is an HTTP client library for Python. From 1.23 to before 2.7.0, cross-origin redirects followed from the low-level API via ProxyManager.connection_from_url().urlopen(..., assert_same_host=False) still forward these sensitive heade…

Vulnerability class: Information Disclosure

EPSS: 0.000 (2.2th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N.

Affected products

Python Urllib3
Urllib3 — versions >= 1.23, < 2.7.0

Weakness classification (CWE)

CWE-200 — Information Disclosure

References

security-advisories@github.com (x_refsource_CONFIRM, Mitigation, Vendor Advisory)

Frequently asked questions

What is CVE-2026-44431?: CVE-2026-44431 is a medium-severity vulnerability in Python Urllib3, classified under Information Disclosure. CVSS score: 5.3/10. Published 2026-05-13.
How severe is CVE-2026-44431?: Medium severity. CVSS v3 base score is 5.3 out of 10.