FKIE_CVE-2026-115557

Vulnerability from fkie_nvd - Published: 2026-10-24 15:17 - Updated: 2026-10-26 01:17
Severity
9.4 (Critical) - 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
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.
References
cna@python.orghttp://www.openwall.com/lists/oss-security/2026/10/20/29
cna@python.orghttps://emudhra.we-have-a-problem.com/
cna@python.orghttps://github.com/python/cpython/commit/21a50891ab4be2e9955239e625ae2b40c6b1854d
cna@python.orghttps://github.com/python/cpython/commit/36cd295f32fc9ba19399e01abee91231440a41dd
cna@python.orghttps://github.com/python/cpython/commit/48d9b2712cd52206c7a5882d0fdca4863ed65e93
cna@python.orghttps://github.com/python/cpython/commit/7dd8b4736a1419750b94a388e6d158be15836fe6
cna@python.orghttps://github.com/python/cpython/commit/98f0e4ed349f370dc8a00366da1a9797e11c9ed5
cna@python.orghttps://github.com/python/cpython/commit/a17d9ef549008133eadf20689b1f4787902efe5b
cna@python.orghttps://github.com/python/cpython/commit/af52b41afa4330fb38583db553631baa2f122f90
cna@python.orghttps://github.com/python/cpython/commit/c7fd7edf7e0d122a3973cf676fae21b6aaa650a8
cna@python.orghttps://github.com/python/cpython/commit/e2a9dd97ef9571c710ac0afaa834c8879aebce78
cna@python.orghttps://github.com/python/cpython/commit/e4500d8a437ee5b988a5410cb9b59d177aa01370
cna@python.orghttps://github.com/python/cpython/commit/e4f63e65a93cf44c14274aa987e644b8c003625e
cna@python.orghttps://github.com/python/cpython/commit/e9bf2cf84eebf838a1edaa1c648c2b36345b99d3
cna@python.orghttps://github.com/python/cpython/issues/160040
cna@python.orghttps://github.com/python/cpython/pull/160042
cna@python.orghttps://mail.python.org/archives/list/security-announce@python.org/thread/FNAJMZV6XQYLVPABNINDMF3VF66AYLW4/
af854a3a-2127-422b-91ae-364da2661108http://www.openwall.com/lists/oss-security/2026/10/24/5
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "modules": [
            "ssl"
          ],
          "product": "CPython",
          "repo": "https://github.com/python/cpython",
          "vendor": "Python Software Foundation",
          "versions": [
            {
              "lessThan": "3.11.18",
              "status": "affected",
              "version": "0",
              "versionType": "python"
            },
            {
              "lessThan": "3.12.16",
              "status": "affected",
              "version": "3.12.0",
              "versionType": "python"
            },
            {
              "lessThan": "3.13.18",
              "status": "affected",
              "version": "3.13.0",
              "versionType": "python"
            },
            {
              "lessThan": "3.16.0",
              "status": "affected",
              "version": "3.14.0a1",
              "versionType": "python"
            }
          ]
        }
      ],
      "source": "cna@python.org"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "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."
    }
  ],
  "id": "CVE-2026-115557",
  "lastModified": "2026-10-26T01:17:14.870",
  "metrics": {
    "cvssMetricV40": [
      {
        "cvssData": {
          "Automatable": "NOT_DEFINED",
          "Recovery": "NOT_DEFINED",
          "Safety": "NOT_DEFINED",
          "attackComplexity": "LOW",
          "attackRequirements": "NONE",
          "attackVector": "NETWORK",
          "availabilityRequirement": "NOT_DEFINED",
          "baseScore": 9.4,
          "baseSeverity": "CRITICAL",
          "confidentialityRequirement": "NOT_DEFINED",
          "exploitMaturity": "NOT_DEFINED",
          "integrityRequirement": "NOT_DEFINED",
          "modifiedAttackComplexity": "NOT_DEFINED",
          "modifiedAttackRequirements": "NOT_DEFINED",
          "modifiedAttackVector": "NOT_DEFINED",
          "modifiedPrivilegesRequired": "NOT_DEFINED",
          "modifiedSubAvailabilityImpact": "NOT_DEFINED",
          "modifiedSubConfidentialityImpact": "NOT_DEFINED",
          "modifiedSubIntegrityImpact": "NOT_DEFINED",
          "modifiedUserInteraction": "NOT_DEFINED",
          "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
          "modifiedVulnConfidentialityImpact": "NOT_DEFINED",
          "modifiedVulnIntegrityImpact": "NOT_DEFINED",
          "privilegesRequired": "NONE",
          "providerUrgency": "NOT_DEFINED",
          "subAvailabilityImpact": "HIGH",
          "subConfidentialityImpact": "HIGH",
          "subIntegrityImpact": "HIGH",
          "userInteraction": "PASSIVE",
          "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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
          "version": "4.0",
          "vulnAvailabilityImpact": "HIGH",
          "vulnConfidentialityImpact": "HIGH",
          "vulnIntegrityImpact": "HIGH",
          "vulnerabilityResponseEffort": "NOT_DEFINED"
        },
        "source": "cna@python.org",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-10-24T15:17:33.600",
  "references": [
    {
      "source": "cna@python.org",
      "url": "http://www.openwall.com/lists/oss-security/2026/10/20/29"
    },
    {
      "source": "cna@python.org",
      "url": "https://emudhra.we-have-a-problem.com/"
    },
    {
      "source": "cna@python.org",
      "url": "https://github.com/python/cpython/commit/21a50891ab4be2e9955239e625ae2b40c6b1854d"
    },
    {
      "source": "cna@python.org",
      "url": "https://github.com/python/cpython/commit/36cd295f32fc9ba19399e01abee91231440a41dd"
    },
    {
      "source": "cna@python.org",
      "url": "https://github.com/python/cpython/commit/48d9b2712cd52206c7a5882d0fdca4863ed65e93"
    },
    {
      "source": "cna@python.org",
      "url": "https://github.com/python/cpython/commit/7dd8b4736a1419750b94a388e6d158be15836fe6"
    },
    {
      "source": "cna@python.org",
      "url": "https://github.com/python/cpython/commit/98f0e4ed349f370dc8a00366da1a9797e11c9ed5"
    },
    {
      "source": "cna@python.org",
      "url": "https://github.com/python/cpython/commit/a17d9ef549008133eadf20689b1f4787902efe5b"
    },
    {
      "source": "cna@python.org",
      "url": "https://github.com/python/cpython/commit/af52b41afa4330fb38583db553631baa2f122f90"
    },
    {
      "source": "cna@python.org",
      "url": "https://github.com/python/cpython/commit/c7fd7edf7e0d122a3973cf676fae21b6aaa650a8"
    },
    {
      "source": "cna@python.org",
      "url": "https://github.com/python/cpython/commit/e2a9dd97ef9571c710ac0afaa834c8879aebce78"
    },
    {
      "source": "cna@python.org",
      "url": "https://github.com/python/cpython/commit/e4500d8a437ee5b988a5410cb9b59d177aa01370"
    },
    {
      "source": "cna@python.org",
      "url": "https://github.com/python/cpython/commit/e4f63e65a93cf44c14274aa987e644b8c003625e"
    },
    {
      "source": "cna@python.org",
      "url": "https://github.com/python/cpython/commit/e9bf2cf84eebf838a1edaa1c648c2b36345b99d3"
    },
    {
      "source": "cna@python.org",
      "url": "https://github.com/python/cpython/issues/160040"
    },
    {
      "source": "cna@python.org",
      "url": "https://github.com/python/cpython/pull/160042"
    },
    {
      "source": "cna@python.org",
      "url": "https://mail.python.org/archives/list/security-announce@python.org/thread/FNAJMZV6XQYLVPABNINDMF3VF66AYLW4/"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "url": "http://www.openwall.com/lists/oss-security/2026/10/24/5"
    }
  ],
  "sourceIdentifier": "cna@python.org",
  "vulnStatus": "Received",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-299"
        }
      ],
      "source": "cna@python.org",
      "type": "Secondary"
    }
  ]
}



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