{"cve":"CVE-2026-42561","nvd":{"published":"2026-05-13T21:16:47.070","modified":"2026-10-26T14:10:00.130","status":"Deferred","description":"Python-Multipart is a streaming multipart parser for Python. Prior to 0.0.27, python-multipart has a denial of service vulnerability in multipart part header parsing. When parsing multipart/form-data, MultipartParser previously had no limit on the number of part headers or the size of an individual part header. An attacker could send a request with either many repeated headers without terminating the header block or a single very large header value, causing excessive CPU work before request rejection or completion. This vulnerability is fixed in 0.0.27.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","score":7.5},"cwes":["CWE-770","CWE-606"],"references":["https://github.com/Kludex/python-multipart/security/advisories/GHSA-pp6c-gr5w-3c5g","https://access.redhat.com/errata/RHSA-2026:37275","https://access.redhat.com/errata/RHSA-2026:42132","https://access.redhat.com/errata/RHSA-2026:42142","https://access.redhat.com/errata/RHSA-2026:43038"],"products":[],"source":"nvd","synced_at":"2026-10-26T14:27:29.784594657+00:00"},"epss":{"cve":"CVE-2026-42561","score":0.0074,"percentile":0.54349,"date":"2026-10-26"},"kev":null,"osv":[{"id":"GHSA-pp6c-gr5w-3c5g","url":"https://osv.dev/vulnerability/GHSA-pp6c-gr5w-3c5g","summary":"python-multipart has Denial of Service via unbounded multipart part headers","modified":"2026-09-10T03:50:47.215892833Z","packages":[{"ecosystem":"PyPI","name":"python-multipart","purl":"pkg:pypi/python-multipart","ranges":["<0.0.27"],"fixed":["0.0.27"]}]},{"id":"PYSEC-2026-3039","url":"https://osv.dev/vulnerability/PYSEC-2026-3039","summary":"python-multipart has Denial of Service via unbounded multipart part headers","modified":"2026-07-13T16:33:29.070412322Z","packages":[{"ecosystem":"PyPI","name":"python-multipart","purl":"pkg:pypi/python-multipart","ranges":["<0.0.27"],"fixed":["0.0.27"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}