{"id":"CVE-2026-40347","state":"PUBLISHED","title":"Python-Multipart affected by Denial of Service via large multipart preamble or epilogue data","description":"Python-Multipart is a streaming multipart parser for Python. Versions prior to 0.0.26 have a denial of service vulnerability when parsing crafted `multipart/form-data` requests with large preamble or epilogue sections. Upgrade to version 0.0.26 or later, which skips ahead to the next boundary candidate when processing leading CR/LF data and immediately discards epilogue data after the closing boundary.","publishedAt":"2026-04-17T23:56:50.777Z","updatedAt":"2026-04-20T15:46:40.011Z","severity":{"score":5.3,"label":"Medium","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","source":"GitHub_M"},"assigner":"GitHub_M","products":["Kludex python-multipart"],"affected":[{"vendor":"Kludex","product":"python-multipart","versions":[{"version":"< 0.0.26","status":"affected"}]}],"references":["https://github.com/Kludex/python-multipart/security/advisories/GHSA-mj87-hwqh-73pj","https://github.com/Kludex/python-multipart/releases/tag/0.0.26"],"weaknesses":["CWE-400","CWE-834"],"ingestedAt":"2026-10-29T20:11:57.932Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/40xxx/CVE-2026-40347.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-40347","state":"PUBLISHED","datePublished":"2026-04-17T23:56:50.777Z","dateUpdated":"2026-04-20T15:46:40.011Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-04-10T22:50:01.358Z"},"containers":{"cna":{"title":"Python-Multipart affected by Denial of Service via large multipart preamble or epilogue data","descriptions":[{"lang":"en","value":"Python-Multipart is a streaming multipart parser for Python. Versions prior to 0.0.26 have a denial of service vulnerability when parsing crafted `multipart/form-data` requests with large preamble or epilogue sections. Upgrade to version 0.0.26 or later, which skips ahead to the next boundary candidate when processing leading CR/LF data and immediately discards epilogue data after the closing boundary."}],"affected":[{"vendor":"Kludex","product":"python-multipart","versions":[{"version":"< 0.0.26","status":"affected"}]}],"references":[{"url":"https://github.com/Kludex/python-multipart/security/advisories/GHSA-mj87-hwqh-73pj","name":"https://github.com/Kludex/python-multipart/security/advisories/GHSA-mj87-hwqh-73pj","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/Kludex/python-multipart/releases/tag/0.0.26","name":"https://github.com/Kludex/python-multipart/releases/tag/0.0.26","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"LOW","baseScore":5.3,"baseSeverity":"MEDIUM","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:L","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-400","lang":"en","description":"CWE-400: Uncontrolled Resource Consumption","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-834","lang":"en","description":"CWE-834: Excessive Iteration","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-04-17T23:56:50.777Z"},"source":{"advisory":"GHSA-mj87-hwqh-73pj","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-04-20T15:46:36.258461Z","id":"CVE-2026-40347","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":"2026-04-20T15:46:40.011Z"}}]}}}