CVE-2018-25091: Python URLLIB3

Medium severity, CVSS 6.1. EPSS: 0.5% chance of exploitation in the next 30 days.

urllib3 before 1.24.2 does not remove the authorization HTTP header when following a cross-origin redirect (i.e., a redirect that differs in host, port, or scheme). This can allow for credentials in the authorization header to be exposed to unintended hosts or transmitted in cleartext. NOTE: this issue exists because of an incomplete fix for CVE-2018-20060 (which was case-sensitive).

Affected products

• Python URLLIB3: before 1.24.2 (fixed in 1.24.2)

Published 2023-10-15. Last modified 2026-06-17.