{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-3298",
        "assignerOrgId": "28c92f92-d60d-412d-b760-e73465c3df22",
        "state": "PUBLISHED",
        "assignerShortName": "PSF",
        "dateReserved": "2026-02-26T20:12:47.041Z",
        "datePublished": "2026-04-21T14:45:01.919Z",
        "dateUpdated": "2026-08-13T00:27:55.667Z"
    },
    "containers": {
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                    "defaultStatus": "unaffected",
                    "product": "CPython",
                    "repo": "https://github.com/python/cpython",
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                            "versionType": "python"
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                            "version": "3.12.0",
                            "lessThan": "3.12.14",
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                            "version": "3.13.0",
                            "lessThan": "3.13.14",
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                            "version": "3.15.0a1",
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                            "versionType": "python"
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                    ]
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            ],
            "credits": [
                {
                    "lang": "en",
                    "type": "reporter",
                    "value": "GGAutomaton (https://github.com/GGAutomaton)"
                },
                {
                    "lang": "en",
                    "type": "remediation reviewer",
                    "value": "Victor Stinner (https://github.com/vstinner)"
                },
                {
                    "lang": "en",
                    "type": "coordinator",
                    "value": "Seth Larson (https://github.com/sethmlarson)"
                }
            ],
            "descriptions": [
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                    "lang": "en",
                    "supportingMedia": [
                        {
                            "type": "text/html",
                            "value": "The method \"sock_recvfrom_into()\" of \"asyncio.ProacterEventLoop\" (Windows only) was missing a boundary check for the data buffer when using nbytes parameter. This allowed for an out-of-bounds buffer write if data was larger than the buffer size. Non-Windows platforms are not affected."
                        }
                    ],
                    "value": "The method \"sock_recvfrom_into()\" of \"asyncio.ProacterEventLoop\" (Windows only) was missing a boundary check for the data buffer when using nbytes parameter. This allowed for an out-of-bounds buffer write if data was larger than the buffer size. Non-Windows platforms are not affected."
                }
            ],
            "metrics": [
                {
                    "cvssV4_0": {
                        "Automatable": "NOT_DEFINED",
                        "Recovery": "NOT_DEFINED",
                        "Safety": "NOT_DEFINED",
                        "attackComplexity": "LOW",
                        "attackRequirements": "NONE",
                        "attackVector": "NETWORK",
                        "baseScore": 8.8,
                        "baseSeverity": "HIGH",
                        "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:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:H/SC:N/SI:N/SA:N",
                        "version": "4.0",
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                        "vulnerabilityResponseEffort": "NOT_DEFINED"
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                    "format": "CVSS",
                    "scenarios": [
                        {
                            "lang": "en",
                            "value": "GENERAL"
                        }
                    ]
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            ],
            "problemTypes": [
                {
                    "descriptions": [
                        {
                            "cweId": "CWE-787",
                            "description": "CWE-787 Out-of-bounds write",
                            "lang": "en",
                            "type": "CWE"
                        }
                    ]
                }
            ],
            "providerMetadata": {
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                "dateUpdated": "2026-08-13T00:27:55.667Z"
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            "references": [
                {
                    "tags": [
                        "patch"
                    ],
                    "url": "https://github.com/python/cpython/pull/148809"
                },
                {
                    "tags": [
                        "issue-tracking"
                    ],
                    "url": "https://github.com/python/cpython/issues/148808"
                },
                {
                    "tags": [
                        "vendor-advisory"
                    ],
                    "url": "https://mail.python.org/archives/list/security-announce@python.org/thread/KWTPIQBOOOUNQP7UFSLBI437NJDFLA3F/"
                },
                {
                    "tags": [
                        "patch"
                    ],
                    "url": "https://github.com/python/cpython/commit/1274766d3c29007ab77245a72abbf8dce2a9db4d"
                },
                {
                    "tags": [
                        "patch"
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                    "url": "https://github.com/python/cpython/commit/27522b7d6e6588f03e61099dd858cd5a9314e2f2"
                },
                {
                    "tags": [
                        "patch"
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                    "tags": [
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                    ],
                    "url": "https://github.com/python/cpython/commit/6c8b85b3f1d83d5697ec19880960e1eacee56688"
                },
                {
                    "tags": [
                        "patch"
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                    "url": "https://github.com/python/cpython/commit/f5ca38739241fe7a40a4b116d5a8a1364dd6fea7"
                }
            ],
            "source": {
                "discovery": "UNKNOWN"
            },
            "title": "Out-of-bounds write in Windows asyncio.ProacterEventLoop.sock_recvfrom_into() when using nbytes",
            "x_generator": {
                "engine": "cvelib 1.8.0"
            }
        },
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                "metrics": [
                    {
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                            "type": "ssvc",
                            "content": {
                                "timestamp": "2026-04-21T19:15:36.206348Z",
                                "id": "CVE-2026-3298",
                                "options": [
                                    {
                                        "Exploitation": "none"
                                    },
                                    {
                                        "Automatable": "no"
                                    },
                                    {
                                        "Technical Impact": "partial"
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                                ],
                                "role": "CISA Coordinator",
                                "version": "2.0.3"
                            }
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                "title": "CISA ADP Vulnrichment",
                "providerMetadata": {
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                    "dateUpdated": "2026-04-21T19:15:44.557Z"
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}