Skip to content
Heist/ feed
Back to feed
Low

Security advisory

Type: advisorySources: OSVCVE: 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 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.

Products
Not specified
Affected versions
Not specified
Fixed versions
Not specified
CVEs
CVE-2016-9015
Confirmed fixed CVEs
Not specified
Updated in this feed
1 Nov 2026, 06:20 UTC · Revision 1

Source evidence

CVE-2016-9015

core-osv · Original source

Published 11 Jan 2017, 16:59 UTC

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.

osv:CVE-2016-9015
Complete source record
{
  "id": "a001af57dba6b5a8d8935cbf2665ce70a088da4ad1ced005b84878116f43b080",
  "url": "https://osv.dev/vulnerability/CVE-2016-9015",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2016-9015",
    "summary": "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.",
    "evidence": "osv:CVE-2016-9015",
    "products": [],
    "severity": "low",
    "structured": {
      "id": "CVE-2016-9015",
      "aliases": [
        "CVE-2016-9015",
        "GHSA-v4w5-p2hg-8fh6",
        "PYSEC-2017-98"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/urllib3/urllib3",
              "type": "GIT",
              "events": [
                {
                  "introduced": "a8948b82f1a54c8f5ffabb01c52f2098785013a2"
                },
                {
                  "last_affected": "7d01b990cf77b33659e562189e6962862b292170"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:python:urllib3:1.17:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "1.17"
                      },
                      {
                        "last_affected": "1.17"
                      }
                    ],
                    "source": "CPE_STRING"
                  },
                  {
                    "cpe": "cpe:2.3:a:python:urllib3:1.18:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "1.18"
                      },
                      {
                        "last_affected": "1.18"
                      }
                    ],
                    "source": "CPE_STRING"
                  }
                ]
              }
            }
          ],
          "versions": [
            "1.17",
            "1.18"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2016-9015.json"
          }
        }
      ],
      "modified": "2026-10-24T10:30:38.131894746Z",
      "provider": "osv",
      "references": [],
      "provider_metadata": {}
    },
    "related_cves": [
      {
        "value": "CVE-2016-9015",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 434371,
  "published_at": "2017-01-11T16:59:00.347+00:00"
}