Distrust compromised intermediate certificates in ssl module

{
  "id": "968576f1ccee130f856bcd1029057e9be635207d7dde2b4233f591ba406177af",
  "url": "https://www.cve.org/CVERecord?id=CVE-2026-115557",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Distrust compromised intermediate certificates in ssl module",
    "summary": "Python has added a denylist for known compromised certificates to the \"ssl\" module to ensure user safety even without certificate revocation configured. Known compromised certificates will automatically be rejected regardless of the SSLContext policy configuration.",
    "evidence": "cve:CVE-2026-115557",
    "products": [
      {
        "name": {
          "value": "CPython",
          "evidence": "/containers/cna/affected/0/product"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": []
      }
    ],
    "severity": "critical",
    "structured": {
      "id": "CVE-2026-115557",
      "aliases": [
        "CVE-2026-115557"
      ],
      "metrics": [
        {
          "format": "CVSS",
          "cvssV4_0": {
            "Safety": "NOT_DEFINED",
            "version": "4.0",
            "Recovery": "NOT_DEFINED",
            "baseScore": 9.4,
            "Automatable": "NOT_DEFINED",
            "attackVector": "NETWORK",
            "baseSeverity": "CRITICAL",
            "valueDensity": "NOT_DEFINED",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H",
            "exploitMaturity": "NOT_DEFINED",
            "providerUrgency": "NOT_DEFINED",
            "userInteraction": "PASSIVE",
            "attackComplexity": "LOW",
            "attackRequirements": "NONE",
            "privilegesRequired": "NONE",
            "subIntegrityImpact": "HIGH",
            "vulnIntegrityImpact": "HIGH",
            "subAvailabilityImpact": "HIGH",
            "vulnAvailabilityImpact": "HIGH",
            "subConfidentialityImpact": "HIGH",
            "vulnConfidentialityImpact": "HIGH",
            "vulnerabilityResponseEffort": "NOT_DEFINED"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "GENERAL"
            }
          ]
        }
      ],
      "affected": [
        {
          "repo": "https://github.com/python/cpython",
          "vendor": "Python Software Foundation",
          "modules": [
            "ssl"
          ],
          "product": "CPython",
          "versions": [
            {
              "status": "affected",
              "version": "0",
              "lessThan": "3.11.18",
              "versionType": "python"
            },
            {
              "status": "affected",
              "version": "3.12.0",
              "lessThan": "3.12.16",
              "versionType": "python"
            },
            {
              "status": "affected",
              "version": "3.13.0",
              "lessThan": "3.13.18",
              "versionType": "python"
            },
            {
              "status": "affected",
              "version": "3.14.0",
              "lessThan": "3.14.10",
              "versionType": "python"
            },
            {
              "status": "affected",
              "version": "3.15.0",
              "lessThan": "3.15.2",
              "versionType": "python"
            },
            {
              "status": "affected",
              "version": "3.16.0a1",
              "lessThan": "3.16.0",
              "versionType": "python"
            }
          ],
          "defaultStatus": "unaffected"
        }
      ],
      "modified": "2026-10-27T00:36:07.516Z",
      "provider": "cve",
      "references": [
        "https://github.com/python/cpython/pull/160042",
        "https://github.com/python/cpython/issues/160040",
        "https://emudhra.we-have-a-problem.com/",
        "https://mail.python.org/archives/list/security-announce@python.org/thread/FNAJMZV6XQYLVPABNINDMF3VF66AYLW4/",
        "https://github.com/python/cpython/commit/21a50891ab4be2e9955239e625ae2b40c6b1854d",
        "https://github.com/python/cpython/commit/36cd295f32fc9ba19399e01abee91231440a41dd",
        "https://github.com/python/cpython/commit/48d9b2712cd52206c7a5882d0fdca4863ed65e93",
        "https://github.com/python/cpython/commit/7dd8b4736a1419750b94a388e6d158be15836fe6",
        "https://github.com/python/cpython/commit/98f0e4ed349f370dc8a00366da1a9797e11c9ed5",
        "https://github.com/python/cpython/commit/a17d9ef549008133eadf20689b1f4787902efe5b",
        "https://github.com/python/cpython/commit/af52b41afa4330fb38583db553631baa2f122f90",
        "https://github.com/python/cpython/commit/c7fd7edf7e0d122a3973cf676fae21b6aaa650a8",
        "https://github.com/python/cpython/commit/e2a9dd97ef9571c710ac0afaa834c8879aebce78",
        "https://github.com/python/cpython/commit/e4500d8a437ee5b988a5410cb9b59d177aa01370",
        "https://github.com/python/cpython/commit/e4f63e65a93cf44c14274aa987e644b8c003625e",
        "https://github.com/python/cpython/commit/e9bf2cf84eebf838a1edaa1c648c2b36345b99d3"
      ],
      "provider_metadata": {
        "adp": [
          {
            "title": "CVE Program Container",
            "references": [
              {
                "url": "http://www.openwall.com/lists/oss-security/2026/10/24/5"
              }
            ],
            "providerMetadata": {
              "orgId": "af854a3a-2127-422b-91ae-364da2661108",
              "shortName": "CVE",
              "dateUpdated": "2026-10-24T18:07:53.662Z"
            }
          }
        ],
        "cna": {
          "orgId": "28c92f92-d60d-412d-b760-e73465c3df22",
          "shortName": "PSF",
          "dateUpdated": "2026-10-27T00:36:07.516Z"
        }
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-115557",
        "evidence": "/cveMetadata/cveId"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/containers/cna/metrics"
  },
  "source_id": "core-cve",
  "document_id": 372981,
  "published_at": "2026-10-24T14:15:14.283+00:00"
}