{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-82397",
        "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "state": "PUBLISHED",
        "assignerShortName": "GitHub_M",
        "dateReserved": "2026-08-28T22:00:43.512Z",
        "datePublished": "2026-08-31T21:28:13.958Z",
        "dateUpdated": "2026-08-31T21:28:13.958Z"
    },
    "containers": {
        "cna": {
            "title": "Tornado: Urlencoded body parsing omits max_num_fields, so one request can stall the event loop",
            "problemTypes": [
                {
                    "descriptions": [
                        {
                            "cweId": "CWE-400",
                            "lang": "en",
                            "description": "CWE-400: Uncontrolled Resource Consumption",
                            "type": "CWE"
                        }
                    ]
                },
                {
                    "descriptions": [
                        {
                            "cweId": "CWE-1284",
                            "lang": "en",
                            "description": "CWE-1284: Improper Validation of Specified Quantity in Input",
                            "type": "CWE"
                        }
                    ]
                }
            ],
            "metrics": [
                {
                    "cvssV3_1": {
                        "attackComplexity": "LOW",
                        "attackVector": "NETWORK",
                        "availabilityImpact": "HIGH",
                        "baseScore": 7.5,
                        "baseSeverity": "HIGH",
                        "confidentialityImpact": "NONE",
                        "integrityImpact": "NONE",
                        "privilegesRequired": "NONE",
                        "scope": "UNCHANGED",
                        "userInteraction": "NONE",
                        "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
                        "version": "3.1"
                    }
                }
            ],
            "references": [
                {
                    "name": "https://github.com/tornadoweb/tornado/security/advisories/GHSA-mpf4-983q-p7j4",
                    "tags": [
                        "x_refsource_CONFIRM"
                    ],
                    "url": "https://github.com/tornadoweb/tornado/security/advisories/GHSA-mpf4-983q-p7j4"
                },
                {
                    "name": "https://github.com/tornadoweb/tornado/pull/3704",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/tornadoweb/tornado/pull/3704"
                },
                {
                    "name": "https://github.com/tornadoweb/tornado/commit/8d6363ed7b69d5f0da806efe34d256627a2191de",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/tornadoweb/tornado/commit/8d6363ed7b69d5f0da806efe34d256627a2191de"
                },
                {
                    "name": "https://github.com/tornadoweb/tornado/releases/tag/v6.5.8",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/tornadoweb/tornado/releases/tag/v6.5.8"
                }
            ],
            "affected": [
                {
                    "vendor": "tornadoweb",
                    "product": "tornado",
                    "versions": [
                        {
                            "version": "< 6.5.8",
                            "status": "affected"
                        }
                    ]
                }
            ],
            "providerMetadata": {
                "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
                "shortName": "GitHub_M",
                "dateUpdated": "2026-08-31T21:28:13.958Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "Tornado is a Python web framework and asynchronous networking library. Prior to 6.5.8, Tornado parses application/x-www-form-urlencoded request bodies with urllib.parse.parse_qs in tornado/escape.py without passing max_num_fields. RequestHandler._execute in tornado/web.py parses the body before handler dispatch through HTTPServerRequest._parse_body and parse_body_arguments in tornado/httputil.py, so an unauthenticated request body containing millions of separator-delimited fields can synchronously stall the single-threaded event loop and delay every connection. The body is bounded only by max_buffer_size, which defaults to 104857600 bytes. This issue is fixed in version 6.5.8."
                }
            ],
            "source": {
                "advisory": "GHSA-mpf4-983q-p7j4",
                "discovery": "UNKNOWN"
            }
        }
    }
}