CVE-2026-55553: urllib: Cross-origin redirects preserve credential-bearing request headers, leading to potential credential leakage

Overview

Severity

High (CVSS 7.5)

CVSS Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Exploit Status

Not Exploited

Patch Tuesday

2026-Aug

Released

2026-10-21

EPSS Score

0.66% (percentile: 51.0%)

Affected Products (1)

Other

• 0-17084

Revision History

• 2026-10-21: Information published.