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CVE-2016-9015

Versions 1.17 and 1.18 of the Python urllib3 library suffer from a vulnerability that can cause them, in certain configurations, to not…

Low3.7EPSS 0.75%
Published
Updated
Reserved
Assigned by
mitre

Description

Versions 1.17 and 1.18 of the Python urllib3 library suffer from a vulnerability that can cause them, in certain configurations, to not correctly validate TLS certificates. This places users of the library with those configurations at risk of man-in-the-middle and information leakage attacks. This vulnerability affects users using versions 1.17 and 1.18 of the urllib3 library, who are using the optional PyOpenSSL support for TLS instead of the regular standard library TLS backend, and who are using OpenSSL 1.1.0 via PyOpenSSL. This is an extremely uncommon configuration, so the security impact of this vulnerability is low.

Scores

CVSS scores of CVE-2016-9015, by who scored it
Scored byCVSSScoreVector
NVDNVD · Modified3.0Low3.7CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N
EPSS (exploitation in 30 days)
0.75% · top 45% of all CVEs (2 Nov 2026)

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The list uses the assigner's score when there is one, then CISA's, then NVD's: Low 3.7.

Weakness

Affected products

  • n/a

    • affected n/a

Affected packages

From reviewed advisories of the GitHub Advisory Database.

References (2)

Sources

The same CVE in the primary databases and aggregators, to check against.

Record last updated .