{"id":"CVE-2016-9015","url":"https://www.cyber-defence.io/tools/cve/CVE-2016-9015","generatedAt":"2026-10-28T20:05:58.401Z","title":"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.","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.","published":"2017-01-11T16:59:00.000Z","lastModified":"2026-06-17T00:55:18.000Z","status":"Modified","sourceIdentifier":"cve@mitre.org","cvss":{"version":"3.0","score":3.7,"severity":"LOW","vector":"CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N"},"cwe":["CWE-295"],"affected":["python/urllib3"],"epss":{"score":0.00754,"percentile":0.54873,"date":"2026-10-27","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (0.75%). Track it; it rarely justifies an emergency change on its own."},"changes":[],"references":[{"url":"http://www.openwall.com/lists/oss-security/2016/10/27/6","tags":["Mailing List","Mitigation"],"source":"cve@mitre.org"},{"url":"http://www.securityfocus.com/bid/93941","tags":["Third Party Advisory","VDB Entry"],"source":"cve@mitre.org"},{"url":"http://www.openwall.com/lists/oss-security/2016/10/27/6","tags":["Mailing List","Mitigation"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"http://www.securityfocus.com/bid/93941","tags":["Third Party Advisory","VDB Entry"],"source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2016-9015","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}