{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-19445",
        "assignerOrgId": "28c92f92-d60d-412d-b760-e73465c3df22",
        "state": "PUBLISHED",
        "assignerShortName": "PSF",
        "dateReserved": "2026-08-10T13:31:21.724Z",
        "datePublished": "2026-09-30T16:16:04.923Z",
        "dateUpdated": "2026-10-03T00:36:46.398Z"
    },
    "containers": {
        "cna": {
            "affected": [
                {
                    "defaultStatus": "unaffected",
                    "modules": [
                        "ssl"
                    ],
                    "product": "CPython",
                    "repo": "https://github.com/python/cpython",
                    "vendor": "Python Software Foundation",
                    "versions": [
                        {
                            "version": "0",
                            "lessThan": "3.10.22",
                            "status": "affected",
                            "versionType": "python"
                        },
                        {
                            "version": "3.11.0",
                            "lessThan": "3.11.17",
                            "status": "affected",
                            "versionType": "python"
                        },
                        {
                            "version": "3.12.0",
                            "lessThan": "3.12.15",
                            "status": "affected",
                            "versionType": "python"
                        },
                        {
                            "version": "3.13.0",
                            "lessThan": "3.13.16",
                            "status": "affected",
                            "versionType": "python"
                        },
                        {
                            "version": "3.14.0",
                            "lessThan": "3.14.8",
                            "status": "affected",
                            "versionType": "python"
                        },
                        {
                            "version": "3.15.0a1",
                            "lessThan": "3.15.0rc3",
                            "status": "affected",
                            "versionType": "python"
                        }
                    ]
                }
            ],
            "credits": [
                {
                    "lang": "en",
                    "type": "reporter",
                    "value": "Gregory P. Smith (https://github.com/gpshead)"
                },
                {
                    "lang": "en",
                    "type": "coordinator",
                    "value": "Seth Larson (https://github.com/sethmlarson)"
                },
                {
                    "lang": "en",
                    "type": "remediation reviewer",
                    "value": "Bénédikt Tran (https://github.com/picnixz)"
                }
            ],
            "descriptions": [
                {
                    "lang": "en",
                    "supportingMedia": [
                        {
                            "type": "text/html",
                            "value": "<p>A remote, unauthenticated TLS client can make a server crash or call\nthrough a freed pointer if its sni_callback assigns a different context to\nSSLSocket.context (the documented way to select a certificate per server\nname) and nothing else keeps the original ssl.SSLContext alive. Typical\ncases are servers that create an SSLContext per connection or replace it\nwhile connections are open; servers that wrap their listening socket with\nit are not affected.</p>\n<p>Mitigation: keep a reference to every SSLContext that sets sni_callback for\nthe lifetime of the server. TLS clients are not affected.</p>"
                        }
                    ],
                    "value": "A remote, unauthenticated TLS client can make a server crash or call\nthrough a freed pointer if its sni_callback assigns a different context to\nSSLSocket.context (the documented way to select a certificate per server\nname) and nothing else keeps the original ssl.SSLContext alive. Typical\ncases are servers that create an SSLContext per connection or replace it\nwhile connections are open; servers that wrap their listening socket with\nit are not affected.\n\n\nMitigation: keep a reference to every SSLContext that sets sni_callback for\nthe lifetime of the server. TLS clients are not affected."
                }
            ],
            "metrics": [
                {
                    "cvssV4_0": {
                        "Automatable": "NOT_DEFINED",
                        "Recovery": "NOT_DEFINED",
                        "Safety": "NOT_DEFINED",
                        "attackComplexity": "HIGH",
                        "attackRequirements": "PRESENT",
                        "attackVector": "NETWORK",
                        "baseScore": 9.2,
                        "baseSeverity": "CRITICAL",
                        "exploitMaturity": "NOT_DEFINED",
                        "privilegesRequired": "NONE",
                        "providerUrgency": "NOT_DEFINED",
                        "subAvailabilityImpact": "NONE",
                        "subConfidentialityImpact": "NONE",
                        "subIntegrityImpact": "NONE",
                        "userInteraction": "NONE",
                        "valueDensity": "NOT_DEFINED",
                        "vectorString": "CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:L/SC:N/SI:N/SA:N",
                        "version": "4.0",
                        "vulnAvailabilityImpact": "LOW",
                        "vulnConfidentialityImpact": "HIGH",
                        "vulnIntegrityImpact": "HIGH",
                        "vulnerabilityResponseEffort": "NOT_DEFINED"
                    },
                    "format": "CVSS",
                    "scenarios": [
                        {
                            "lang": "en",
                            "value": "GENERAL"
                        }
                    ]
                }
            ],
            "problemTypes": [
                {
                    "descriptions": [
                        {
                            "cweId": "CWE-416",
                            "description": "CWE-416",
                            "lang": "en",
                            "type": "CWE"
                        }
                    ]
                }
            ],
            "providerMetadata": {
                "orgId": "28c92f92-d60d-412d-b760-e73465c3df22",
                "shortName": "PSF",
                "dateUpdated": "2026-10-03T00:36:46.398Z"
            },
            "references": [
                {
                    "tags": [
                        "patch"
                    ],
                    "url": "https://github.com/python/cpython/pull/158504"
                },
                {
                    "tags": [
                        "vendor-advisory"
                    ],
                    "url": "https://mail.python.org/archives/list/security-announce@python.org/thread/QMQIUQB6WGGC3MI7I3WKQXOYOBDSPPS3/"
                },
                {
                    "tags": [
                        "issue-tracking"
                    ],
                    "url": "https://github.com/python/cpython/issues/156293"
                },
                {
                    "tags": [
                        "patch"
                    ],
                    "url": "https://github.com/python/cpython/commit/34a53dce8174da2fceb12fe084a4def02a10053d"
                },
                {
                    "tags": [
                        "patch"
                    ],
                    "url": "https://github.com/python/cpython/commit/46133cd57d309652139ada74014aca7665ac552b"
                },
                {
                    "tags": [
                        "patch"
                    ],
                    "url": "https://github.com/python/cpython/commit/63fab143d94cafae71850831acfb52041ba44af7"
                },
                {
                    "tags": [
                        "patch"
                    ],
                    "url": "https://github.com/python/cpython/commit/cd7e51e7d4563866fbaa1e2521ae69b45daf3698"
                },
                {
                    "tags": [
                        "patch"
                    ],
                    "url": "https://github.com/python/cpython/commit/d8717ed01717a9641686e6e6f83f0ab8af235e2c"
                },
                {
                    "tags": [
                        "patch"
                    ],
                    "url": "https://github.com/python/cpython/commit/b12968cefe69ca1dcb8606c832ff73ee7dbf4ba8"
                },
                {
                    "tags": [
                        "patch"
                    ],
                    "url": "https://github.com/python/cpython/commit/ec44b5a3258cbda947d5e07242ee562ed05ef24b"
                }
            ],
            "source": {
                "discovery": "UNKNOWN"
            },
            "title": "Use-after-free of a server-side SSLContext when sni_callback switches contexts",
            "x_generator": {
                "engine": "cvelib 1.8.0"
            }
        },
        "adp": [
            {
                "title": "CVE Program Container",
                "references": [
                    {
                        "url": "http://www.openwall.com/lists/oss-security/2026/09/30/17"
                    }
                ],
                "providerMetadata": {
                    "orgId": "af854a3a-2127-422b-91ae-364da2661108",
                    "shortName": "CVE",
                    "dateUpdated": "2026-09-30T18:09:39.735Z"
                }
            }
        ]
    }
}