{"id":"CVE-2026-34516","state":"PUBLISHED","title":"AIOHTTP: Multipart Header Size Bypass","description":"AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to version 3.13.4, a response with an excessive number of multipart headers may be allowed to use more memory than intended, potentially allowing a DoS vulnerability. This issue has been patched in version 3.13.4.","publishedAt":"2026-04-01T20:13:04.893Z","updatedAt":"2026-04-04T03:11:58.583Z","severity":{"score":6.6,"label":"Medium","version":"4.0","vector":"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:U","source":"GitHub_M"},"assigner":"GitHub_M","products":["aio-libs aiohttp"],"affected":[{"vendor":"aio-libs","product":"aiohttp","versions":[{"version":"< 3.13.4","status":"affected"}]}],"references":["https://github.com/aio-libs/aiohttp/security/advisories/GHSA-m5qp-6w8w-w647","https://github.com/aio-libs/aiohttp/commit/8a74257b3804c9aac0bf644af93070f68f6c5a6f","https://github.com/aio-libs/aiohttp/releases/tag/v3.13.4"],"weaknesses":["CWE-770"],"ingestedAt":"2026-10-29T20:11:40.391Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/34xxx/CVE-2026-34516.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-34516","state":"PUBLISHED","datePublished":"2026-04-01T20:13:04.893Z","dateUpdated":"2026-04-04T03:11:58.583Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-03-30T16:03:31.047Z"},"containers":{"cna":{"title":"AIOHTTP: Multipart Header Size Bypass","descriptions":[{"lang":"en","value":"AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to version 3.13.4, a response with an excessive number of multipart headers may be allowed to use more memory than intended, potentially allowing a DoS vulnerability. This issue has been patched in version 3.13.4."}],"affected":[{"vendor":"aio-libs","product":"aiohttp","versions":[{"version":"< 3.13.4","status":"affected"}]}],"references":[{"url":"https://github.com/aio-libs/aiohttp/security/advisories/GHSA-m5qp-6w8w-w647","name":"https://github.com/aio-libs/aiohttp/security/advisories/GHSA-m5qp-6w8w-w647","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/aio-libs/aiohttp/commit/8a74257b3804c9aac0bf644af93070f68f6c5a6f","name":"https://github.com/aio-libs/aiohttp/commit/8a74257b3804c9aac0bf644af93070f68f6c5a6f","tags":["x_refsource_MISC"]},{"url":"https://github.com/aio-libs/aiohttp/releases/tag/v3.13.4","name":"https://github.com/aio-libs/aiohttp/releases/tag/v3.13.4","tags":["x_refsource_MISC"]}],"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":6.6,"baseSeverity":"MEDIUM","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:U","version":"4.0"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-770","lang":"en","description":"CWE-770: Allocation of Resources Without Limits or Throttling","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-04-01T20:13:04.893Z"},"source":{"advisory":"GHSA-m5qp-6w8w-w647","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"cvssV3_1":{"scope":"UNCHANGED","version":"3.1","baseScore":7.5,"attackVector":"NETWORK","baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","integrityImpact":"NONE","userInteraction":"NONE","attackComplexity":"LOW","availabilityImpact":"HIGH","privilegesRequired":"NONE","confidentialityImpact":"NONE"}},{"other":{"type":"ssvc","content":{"timestamp":"2026-04-04T03:11:32.193097Z","id":"CVE-2026-34516","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-04-04T03:11:58.583Z"}}]}}}