CVE-2026-44431 HIGH

CVE-2026-44431: urllib3: Sensitive headers forwarded across origins in proxied low-level redirects

Vendor Urllib3
Product urllib3
Weakness CWE-200 · Info exposure
Published May 13, 2026
Last update May 13, 2026
View on NVD All CVEs

CVSS base score

8.2/10
Attack vector Network
Attack complexity High
Privileges required None
User interaction None
Confidentiality —
Integrity —

CVSS vector

CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N

What the vulnerability does

01Description

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 headers. This vulnerability is fixed in 2.7.0.

Key dates

02Disclosure timeline

May 13, 2026 CVE published
May 13, 2026 Record updated