Exposure of Sensitive Information to an Unauthorized Actor in urllib3
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.
Affected software
Click a technology to see all vulnerabilities affecting it.
| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| Python (PyPI) | urllib3 | < 1.23 | 1.23 |
References
- https://github.com/urllib3/urllib3/pull/1346
- https://github.com/urllib3/urllib3/issues/1316
- https://github.com/urllib3/urllib3/blob/master/CHANGES.rst
- https://bugzilla.redhat.com/show_bug.cgi?id=1649153
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/5SJERZEJDSUYQP7BNBXMBHRHGY26HRZD/
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/XWP36YW3KSVLXDBY3QJKDYEPCIMN3VQZ/
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/BXLAXHM3Z6DUCXZ7ZXZ2EAYJXWDCZFCT/
- https://usn.ubuntu.com/3990-1/
- https://access.redhat.com/errata/RHSA-2019:2272
- http://lists.opensuse.org/opensuse-security-announce/2019-09/msg00039.html
- https://github.com/advisories/GHSA-www2-v7xj-xrc6
- https://nvd.nist.gov/vuln/detail/CVE-2018-20060
- https://github.com/urllib3/urllib3/commit/560bd227b90f74417ffaedebf5f8d05a8ee4f532
- https://usn.ubuntu.com/3990-1
- https://security.netapp.com/advisory/ntap-20241227-0010
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/XWP36YW3KSVLXDBY3QJKDYEPCIMN3VQZ
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/BXLAXHM3Z6DUCXZ7ZXZ2EAYJXWDCZFCT
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/5SJERZEJDSUYQP7BNBXMBHRHGY26HRZD
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/XWP36YW3KSVLXDBY3QJKDYEPCIMN3VQZ
- 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/5SJERZEJDSUYQP7BNBXMBHRHGY26HRZD
- https://lists.debian.org/debian-lts-announce/2021/06/msg00015.html
- https://github.com/urllib3/urllib3
- https://github.com/pypa/advisory-database/tree/main/vulns/urllib3/PYSEC-2018-32.yaml
- CVSS vector
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H- Weakness (CWE)
CWE-200- Platform
- Python (PyPI)
- Package
urllib3- Disclosed
- 11.12.2018
- Updated
- 11.10.2026 12:19
Sources and licenses
OSV / GitHub Advisory Database - PYSEC-2018-32 - PyPA Advisory Database; CC BY 4.0
OSV / GitHub Advisory Database - GHSA-www2-v7xj-xrc6 - CC BY 4.0
Vulnerability history: urllib3
All published vulnerabilities of this package (Python (PyPI)), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 22
- First → latest
- 01.2017 09.2026
- Without a fix
- 0
- Exploited in attacks
- 0
Severity breakdown
- Critical 1
- High 11
- Medium 10
Disclosures per year
- 2017: 1
- 2018: 1
- 2019: 2
- 2020: 2
- 2021: 2
- 2022: 0
- 2023: 3
- 2024: 1
- 2025: 4
- 2026: 6
-
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