CVE-2018-25091

Name: CVE-2018-25091
Creator: NVD / NIST
Published: 2023-10-15T19:15:09.213+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.1/10EPSS 0.51%

Last modified Jun 17, 2026

CVE-2018-25091 is a medium-severity vulnerability rated 6.1/10 on the CVSS scale. 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. EPSS estimates a 0.51% chance of exploitation in the next 30 days.

Description

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).

Metrics

CVSS 3.1

6.1/10

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

EPSS Probability

0.51%

39.7th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-601

Affected Software

Vendor	Product	Versions
Python	Urllib3	< 1.24.2

References

https://github.com/urllib3/urllib3/commit/adb358f8e06865406d1f05e581a16cbea2136fbcPatch
https://github.com/urllib3/urllib3/compare/1.24.1...1.24.2Patch
https://github.com/urllib3/urllib3/issues/1510Issue Tracking, Patch, Vendor Advisory
https://github.com/urllib3/urllib3/commit/adb358f8e06865406d1f05e581a16cbea2136fbcPatch
https://github.com/urllib3/urllib3/compare/1.24.1...1.24.2Patch
https://github.com/urllib3/urllib3/issues/1510Issue Tracking, Patch, Vendor Advisory

Timeline

Published: Oct 15, 2023
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2018-25091?

How severe is CVE-2018-25091?

CVE-2018-25091 has a CVSS score of 6.1/10 (MEDIUM severity). The EPSS model estimates a 0.51% probability of exploitation in the next 30 days.

How do I fix CVE-2018-25091?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2018-25091?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST