CVE-2018-20060

urllib3 before version 1.23 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.

Published: 2018-12-11 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2018-20060 is rated High Risk (74.6/100): CVSS Critical severity, with high exploitation likelihood (EPSS 4.49%, 90th percentile). EPSS ranks this CVE among the most likely to be exploited in the near term. EPSS rose +3.83% over the last day, indicating growing attacker interest. High exploitation likelihood—assess exposure and prioritize remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2018-20060

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.66% 4.49% +3.83%
2 2026-05-07 0.43% 0.66% +0.22%
3 2026-03-04 — 0.43% —

Full EPSS history (55 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2018-20060

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.8 3.0 CRITICAL
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 5.9 [email protected]
5.0 2.0 MEDIUM
AV:N/AC:L/Au:N/C:P/I:N/A:N Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:N)
No availability impact.
 10.0 2.9 [email protected]

Weakness enumeration for CVE-2018-20060

GitHub Security Advisory for CVE-2018-20060

GHSA-www2-v7xj-xrc6 · Severity: critical · Ecosystem: pip — Exposure of Sensitive Information to an Unauthorized Actor in urllib3

OS Trackers for CVE-2018-20060

vendor priority summary link
debian not yet assigned CVE-2018-20060 not yet assigned priority: Debian including 1 source packages (python-urllib3), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2018-20060
redhat medium — https://access.redhat.com/security/cve/CVE-2018-20060
suse medium CVE-2018-20060 severity moderate: SUSE including 341 source package names (amazon/suse-sles-15-sp1-chost-byos-v20210304-hvm-ssd-x86_64, amazon/suse-sles-15-sp1-chost-byos-v20220127-hvm-ssd-x86_64, …), 415 product×package rows across 74 product lines (HPE Helion OpenStack 8, Image SLES12-SP5-Azure-BYOS, … (74 product lines)): Fixed 208, Known Affected 181, Known Not Affected 26. https://www.suse.com/security/cve/CVE-2018-20060/
ubuntu low CVE-2018-20060 low priority: Ubuntu including 1 source packages (python-urllib3), 19 status rows across 19 suites (bionic, cosmic, disco, eoan, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): not-affected 14, released 4, needed 1. https://ubuntu.com/security/CVE-2018-20060

Affected software / configurations for CVE-2018-20060

Vendor Product Version Raw CPE
python urllib3 < 1.23 cpe:2.3:a:python:urllib3:*:*:*:*:*:*:*:*
fedoraproject fedora 28 cpe:2.3:o:fedoraproject:fedora:28:*:*:*:*:*:*:*
fedoraproject fedora 29 cpe:2.3:o:fedoraproject:fedora:29:*:*:*:*:*:*:*
fedoraproject fedora 30 cpe:2.3:o:fedoraproject:fedora:30:*:*:*:*:*:*:*

References for CVE-2018-20060

URL Tags
http://lists.opensuse.org/opensuse-security-announce/2019-09/msg00039.html
https://access.redhat.com/errata/RHSA-2019:2272
https://bugzilla.redhat.com/show_bug.cgi?id=1649153 Issue Tracking Mitigation Patch Third Party Advisory
https://github.com/urllib3/urllib3/blob/master/CHANGES.rst Release Notes Third Party Advisory
https://github.com/urllib3/urllib3/issues/1316 Third Party Advisory
https://github.com/urllib3/urllib3/pull/1346 Third Party Advisory
https://lists.debian.org/debian-lts-announce/2021/06/msg00015.html
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/5SJERZEJDSUYQP7BNBXMBHRHGY26HRZD/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/BXLAXHM3Z6DUCXZ7ZXZ2EAYJXWDCZFCT/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/XWP36YW3KSVLXDBY3QJKDYEPCIMN3VQZ/
https://usn.ubuntu.com/3990-1/
https://security.netapp.com/advisory/ntap-20241227-0010/
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