{"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"}}}}

{}

{"affected": [{"affectedData": [{"product": "tornado", "vendor": "tornadoweb", "versions": [{"status": "affected", "version": "< 6.5.8"}]}], "source": "security-advisories@github.com"}], "cveTags": [], "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."}], "id": "CVE-2026-82397", "lastModified": "2026-08-31T22:17:22.920", "metrics": {"cvssMetricV31": [{"cvssData": {"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"}, "exploitabilityScore": 3.9, "impactScore": 3.6, "source": "security-advisories@github.com", "type": "Secondary"}]}, "published": "2026-08-31T22:17:22.920", "references": [{"source": "security-advisories@github.com", "url": "https://github.com/tornadoweb/tornado/commit/8d6363ed7b69d5f0da806efe34d256627a2191de"}, {"source": "security-advisories@github.com", "url": "https://github.com/tornadoweb/tornado/pull/3704"}, {"source": "security-advisories@github.com", "url": "https://github.com/tornadoweb/tornado/releases/tag/v6.5.8"}, {"source": "security-advisories@github.com", "url": "https://github.com/tornadoweb/tornado/security/advisories/GHSA-mpf4-983q-p7j4"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-400"}, {"lang": "en", "value": "CWE-1284"}], "source": "security-advisories@github.com", "type": "Primary"}]}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[0,6.5.8)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "tornado", "source": "cna", "vendor": "tornadoweb"}, "product": "tornado", "vendor": "tornadoweb"}], "created": "2026-08-31T22:30:06.005805+00:00", "updated": "2026-08-31T22:30:06.185266+00:00", "vendors": ["tornadoweb", "tornadoweb$PRODUCT$tornado"]}