{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-128126", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "state": "PUBLISHED", "assignerShortName": "GitHub_M", "dateReserved": "2026-11-12T22:42:47.032Z", "datePublished": "2026-11-13T20:27:57.071Z", "dateUpdated": "2026-11-13T20:27:57.071Z"}, "containers": {"cna": {"title": "AIOHTTP: Too many URL-encoded form fields block the event loop", "problemTypes": [{"descriptions": [{"cweId": "CWE-407", "lang": "en", "description": "CWE-407: Inefficient Algorithmic Complexity", "type": "CWE"}]}], "metrics": [{"cvssV4_0": {"attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "NONE", "userInteraction": "NONE", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "NONE", "vulnAvailabilityImpact": "HIGH", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "subAvailabilityImpact": "NONE", "baseScore": 8.7, "baseSeverity": "HIGH", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N", "version": "4.0"}}], "references": [{"name": "https://github.com/aio-libs/aiohttp/security/advisories/GHSA-xgw8-8ccx-rmqh", "tags": ["x_refsource_CONFIRM"], "url": "https://github.com/aio-libs/aiohttp/security/advisories/GHSA-xgw8-8ccx-rmqh"}, {"name": "https://github.com/aio-libs/aiohttp/pull/13738", "tags": ["x_refsource_MISC"], "url": "https://github.com/aio-libs/aiohttp/pull/13738"}, {"name": "https://github.com/aio-libs/aiohttp/pull/13741", "tags": ["x_refsource_MISC"], "url": "https://github.com/aio-libs/aiohttp/pull/13741"}, {"name": "https://github.com/aio-libs/aiohttp/commit/615fec3d4f088f30d2ee72cad760152e92aa1c53", "tags": ["x_refsource_MISC"], "url": "https://github.com/aio-libs/aiohttp/commit/615fec3d4f088f30d2ee72cad760152e92aa1c53"}, {"name": "https://github.com/aio-libs/aiohttp/commit/8b0100572936df28977b9de8a6cc7e464c0b521e", "tags": ["x_refsource_MISC"], "url": "https://github.com/aio-libs/aiohttp/commit/8b0100572936df28977b9de8a6cc7e464c0b521e"}, {"name": "https://github.com/aio-libs/aiohttp/releases/tag/v3.14.4", "tags": ["x_refsource_MISC"], "url": "https://github.com/aio-libs/aiohttp/releases/tag/v3.14.4"}], "affected": [{"vendor": "aio-libs", "product": "aiohttp", "versions": [{"version": "< 3.14.4", "status": "affected"}]}], "providerMetadata": {"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "shortName": "GitHub_M", "dateUpdated": "2026-11-13T20:27:57.071Z"}, "descriptions": [{"lang": "en", "value": "AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to 3.14.4, Request.post() does not limit the number of fields in a URL-encoded form body, and inserting many repeated keys into MultiDict takes quadratic time on the event loop. A remote attacker can send a form POST within client_max_size to a handler that calls Request.post() and block the event loop. This issue is fixed in version 3.14.4."}], "source": {"advisory": "GHSA-xgw8-8ccx-rmqh", "discovery": "UNKNOWN"}}}}

{}

{"affected": [{"affectedData": [{"product": "aiohttp", "vendor": "aio-libs", "versions": [{"status": "affected", "version": "< 3.14.4"}]}], "source": "security-advisories@github.com"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to 3.14.4, Request.post() does not limit the number of fields in a URL-encoded form body, and inserting many repeated keys into MultiDict takes quadratic time on the event loop. A remote attacker can send a form POST within client_max_size to a handler that calls Request.post() and block the event loop. This issue is fixed in version 3.14.4."}], "id": "CVE-2026-128126", "lastModified": "2026-11-13T22:11:32.147", "metrics": {"cvssMetricV40": [{"cvssData": {"Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "LOW", "attackRequirements": "NONE", "attackVector": "NETWORK", "availabilityRequirement": "NOT_DEFINED", "baseScore": 8.7, "baseSeverity": "HIGH", "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": "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:N/VI:N/VA:H/SC:N/SI:N/SA:N/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": "NONE", "vulnIntegrityImpact": "NONE", "vulnerabilityResponseEffort": "NOT_DEFINED"}, "source": "security-advisories@github.com", "type": "Secondary"}]}, "published": "2026-11-13T21:17:44.310", "references": [{"source": "security-advisories@github.com", "url": "https://github.com/aio-libs/aiohttp/commit/615fec3d4f088f30d2ee72cad760152e92aa1c53"}, {"source": "security-advisories@github.com", "url": "https://github.com/aio-libs/aiohttp/commit/8b0100572936df28977b9de8a6cc7e464c0b521e"}, {"source": "security-advisories@github.com", "url": "https://github.com/aio-libs/aiohttp/pull/13738"}, {"source": "security-advisories@github.com", "url": "https://github.com/aio-libs/aiohttp/pull/13741"}, {"source": "security-advisories@github.com", "url": "https://github.com/aio-libs/aiohttp/releases/tag/v3.14.4"}, {"source": "security-advisories@github.com", "url": "https://github.com/aio-libs/aiohttp/security/advisories/GHSA-xgw8-8ccx-rmqh"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Awaiting Analysis", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-407"}], "source": "security-advisories@github.com", "type": "Primary"}]}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[0,3.14.4)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "aiohttp", "source": "cna", "vendor": "aio-libs"}, "product": "aiohttp", "vendor": "aio-libs"}], "created": "2026-11-13T22:00:09.001061+00:00", "updated": "2026-11-14T16:45:19.323617+00:00", "vendors": ["aio-libs", "aio-libs$PRODUCT$aiohttp"]}