Improper Certificate Validation in urllib3
The urllib3 library before 1.24.2 for Python mishandles certain cases where the desired set of CA certificates is different from the OS store of CA certificates, which results in SSL connections succeeding in situations where a verification failure is the correct outcome. This is related to use of the ssl_context, ca_certs, or ca_certs_dir argument.
Affected software
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| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| Python (PyPI) | urllib3 | < 1.24.2 | 1.24.2 |
References
- https://github.com/urllib3/urllib3/compare/a6ec68a...1efadf4
- http://www.openwall.com/lists/oss-security/2019/04/19/1
- https://usn.ubuntu.com/3990-1/
- http://lists.opensuse.org/opensuse-security-announce/2019-09/msg00039.html
- http://lists.opensuse.org/opensuse-security-announce/2019-09/msg00041.html
- https://access.redhat.com/errata/RHSA-2019:3335
- https://access.redhat.com/errata/RHSA-2019:3590
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/NKGPJLVLVYCL4L4B4G5TIOTVK4BKPG72/
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/XOSA2NT4DUQDBEIWE6O7KKD24XND7TE2/
- https://github.com/advisories/GHSA-mh33-7rrq-662w
- https://nvd.nist.gov/vuln/detail/CVE-2019-11324
- https://github.com/urllib3/urllib3/commit/1efadf43dc63317cd9eaa3e0fdb9e05ab07254b1
- https://github.com/pypa/advisory-database/tree/main/vulns/urllib3/PYSEC-2019-133.yaml
- https://github.com/urllib3/urllib3
- https://lists.debian.org/debian-lts-announce/2021/06/msg00015.html
- https://lists.debian.org/debian-lts-announce/2023/10/msg00012.html
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/NKGPJLVLVYCL4L4B4G5TIOTVK4BKPG72
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/XOSA2NT4DUQDBEIWE6O7KKD24XND7TE2
- https://pypi.org/project/urllib3/1.24.2
- https://usn.ubuntu.com/3990-1
- CVSS vector
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N- Weakness (CWE)
CWE-295- Platform
- Python (PyPI)
- Package
urllib3- Disclosed
- 18.04.2019
- Updated
- 11.10.2026 11:20
Sources and licenses
OSV / GitHub Advisory Database - PYSEC-2019-133 - PyPA Advisory Database; CC BY 4.0
OSV / GitHub Advisory Database - GHSA-mh33-7rrq-662w - 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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