{"id":"UBUNTU-CVE-2026-42561","details":"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.","modified":"2026-06-30T18:17:45.385530501Z","published":"2026-05-13T21:16:00Z","upstream":["CVE-2026-42561"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-42561"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-42561"},{"type":"REPORT","url":"https://github.com/Kludex/python-multipart/security/advisories/GHSA-pp6c-gr5w-3c5g"},{"type":"REPORT","url":"https://github.com/Kludex/python-multipart/pull/267"},{"type":"REPORT","url":"https://github.com/Kludex/python-multipart/commit/3e64f5f8caba0e5d391b0c1ad0f1c2edf9e8f911"}],"affected":[{"package":{"name":"python-multipart","ecosystem":"Ubuntu:Pro:22.04:LTS","purl":"pkg:deb/ubuntu/python-multipart?arch=source&distro=esm-apps%2Fjammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.0.5-2","0.0.5-2ubuntu0.1~esm1"],"ecosystem_specific":{"binaries":[{"binary_name":"python3-multipart","binary_version":"0.0.5-2ubuntu0.1~esm1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-42561.json"}},{"package":{"name":"python-multipart","ecosystem":"Ubuntu:Pro:24.04:LTS","purl":"pkg:deb/ubuntu/python-multipart?arch=source&distro=esm-apps%2Fnoble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.0.5-3","0.0.6-1","0.0.9-1","0.0.9-1ubuntu0.1~esm1"],"ecosystem_specific":{"binaries":[{"binary_name":"python3-multipart","binary_version":"0.0.9-1ubuntu0.1~esm1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-42561.json"}},{"package":{"name":"python-multipart","ecosystem":"Ubuntu:25.10","purl":"pkg:deb/ubuntu/python-multipart?arch=source&distro=questing"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.0.20-1"],"ecosystem_specific":{"binaries":[{"binary_version":"0.0.20-1","binary_name":"python3-python-multipart"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-42561.json"}},{"package":{"name":"python-multipart","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/python-multipart?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.0.20-1","0.0.20-1.1"],"ecosystem_specific":{"binaries":[{"binary_name":"python3-python-multipart","binary_version":"0.0.20-1.1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-42561.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},{"type":"Ubuntu","score":"medium"}]}