{"schemaVersion":3,"id":"CVE-2026-53539","aliases":["GHSA-5rvq-cxj2-64vf","PYSEC-2026-3036","UBUNTU-CVE-2026-53539","DEBIAN-CVE-2026-53539","CGA-8c37-xqx5-cxh8","CGA-fhmr-jjwv-547q","CGA-353f-gh8h-x6c3","CGA-89rq-345h-c2vr","CGA-cr4p-x6rw-pm9h","CGA-cv6g-36q8-rc5c","CGA-cwh3-pvrm-r4xv","CGA-f5xw-rgp9-j3gm","CGA-hphf-q7rp-qh2m","CGA-mpc5-g544-9qxq","CGA-p9mm-4mpp-hm22","CGA-r4qh-733j-2cm8","CGA-rw4f-xcw3-v64p","CGA-v6ff-grmp-f278","CGA-v95v-7gcm-frvq","CGA-wghp-26xv-hr33","CGA-ww47-579g-c375"],"status":"published","duplicateOf":null,"title":null,"description":"Python-Multipart is a streaming multipart parser for Python. Prior to 0.0.30, when parsing application/x-www-form-urlencoded bodies, QuerystringParser located the field separator with a two step lookup: it first scanned the entire remaining buffer for &, and only when no & existed anywhere ahead did it fall back to scanning for ;. For a body that uses ; as the separator and contains no &, every field iteration performed a full failed & scan over the entire remaining buffer before locating the nearby ;. With N semicolon separated fields in a chunk of size B, this yields O(B^2) byte comparisons per chunk. An attacker can submit a small crafted body of the form a;a;a;... and cause the parser to spend seconds of CPU per request. A handful of concurrent requests can exhaust worker processes. This vulnerability is fixed in 0.0.30.","dates":{"published":"2026-06-22T16:55:42.787Z","modified":"2026-06-23T16:08:36.474Z","reserved":null,"kevAdded":[],"kevDue":[]},"cvss":{"headline":{"score":7.5,"severity":"high","version":"3.1","versionLabel":"v3.1","source":"CVE.org","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","computed":false,"selection":"backend-summary"},"metrics":[{"version":"3.1","versionLabel":"v3.1","source":"CVE.org","score":7.5,"severity":"high","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","exploitability":null,"impact":null,"computed":false},{"version":"3.1","versionLabel":"v3.1","source":"OSV · Pypi","score":7.5,"severity":"high","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","exploitability":10,"impact":6,"computed":true},{"version":"3.1","versionLabel":"v3.1","source":"OSV · Ubuntu","score":7.5,"severity":"high","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","exploitability":10,"impact":6,"computed":true},{"version":"3.1","versionLabel":"v3.1","source":"OSV · Debian","score":7.5,"severity":"high","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","exploitability":10,"impact":6,"computed":true},{"version":"3.1","versionLabel":"v3.1","source":"OSV · Wolfi","score":7.5,"severity":"high","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","exploitability":10,"impact":6,"computed":true},{"version":"3.1","versionLabel":"v3.1","source":"OSV · Chainguard","score":7.5,"severity":"high","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","exploitability":10,"impact":6,"computed":true},{"version":"3.1","versionLabel":"v3.1","source":"NVD","score":7.5,"severity":"high","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","exploitability":null,"impact":null,"computed":false}]},"epss":{"probability":0.0046,"percentile":0.38589,"severity":"low","asOf":"2026-10-20T00:00:00.000Z","change":{"pp":0,"baselineDate":"2026-09-20T00:00:00.000Z","baselineScore":0.0046},"history":[{"date":"2026-09-14T00:00:00.000Z","score":0.0046,"percentile":null},{"date":"2026-09-15T00:00:00.000Z","score":0.0046,"percentile":null},{"date":"2026-09-16T00:00:00.000Z","score":0.0046,"percentile":null},{"date":"2026-09-17T00:00:00.000Z","score":0.0046,"percentile":null},{"date":"2026-09-18T00:00:00.000Z","score":0.0046,"percentile":null},{"date":"2026-09-19T00:00:00.000Z","score":0.0046,"percentile":null},{"date":"2026-09-20T00:00:00.000Z","score":0.0046,"percentile":null},{"date":"2026-09-21T00:00:00.000Z","score":0.0046,"percentile":null},{"date":"2026-09-22T00:00:00.000Z","score":0.0046,"percentile":null},{"date":"2026-09-23T00:00:00.000Z","score":0.0046,"percentile":null},{"date":"2026-09-24T00:00:00.000Z","score":0.0046,"percentile":null},{"date":"2026-09-25T00:00:00.000Z","score":0.0046,"percentile":null},{"date":"2026-09-26T00:00:00.000Z","score":0.0046,"percentile":null},{"date":"2026-09-27T00:00:00.000Z","score":0.0046,"percentile":null},{"date":"2026-09-28T00:00:00.000Z","score":0.0046,"percentile":null},{"date":"2026-09-29T00:00:00.000Z","score":0.0046,"percentile":null},{"date":"2026-09-30T00:00:00.000Z","score":0.0046,"percentile":null},{"date":"2026-10-01T00:00:00.000Z","score":0.0046,"percentile":null},{"date":"2026-10-02T00:00:00.000Z","score":0.0046,"percentile":null},{"date":"2026-10-03T00:00:00.000Z","score":0.0046,"percentile":null},{"date":"2026-10-04T00:00:00.000Z","score":0.0046,"percentile":null},{"date":"2026-10-05T00:00:00.000Z","score":0.0046,"percentile":null},{"date":"2026-10-06T00:00:00.000Z","score":0.0046,"percentile":null},{"date":"2026-10-07T00:00:00.000Z","score":0.0046,"percentile":null},{"date":"2026-10-08T00:00:00.000Z","score":0.0046,"percentile":null},{"date":"2026-10-09T00:00:00.000Z","score":0.0046,"percentile":null},{"date":"2026-10-10T00:00:00.000Z","score":0.0046,"percentile":null},{"date":"2026-10-11T00:00:00.000Z","score":0.0046,"percentile":null},{"date":"2026-10-12T00:00:00.000Z","score":0.0046,"percentile":null},{"date":"2026-10-13T00:00:00.000Z","score":0.0046,"percentile":null},{"date":"2026-10-14T00:00:00.000Z","score":0.0046,"percentile":null},{"date":"2026-10-15T00:00:00.000Z","score":0.0046,"percentile":null},{"date":"2026-10-16T00:00:00.000Z","score":0.0046,"percentile":null},{"date":"2026-10-17T00:00:00.000Z","score":0.0046,"percentile":null},{"date":"2026-10-18T00:00:00.000Z","score":0.0046,"percentile":null},{"date":"2026-10-19T00:00:00.000Z","score":0.0046,"percentile":null},{"date":"2026-10-20T00:00:00.000Z","score":0.0046,"percentile":0.38589}],"last30":[{"date":"2026-09-20T00:00:00.000Z","score":0.0046,"percentile":null},{"date":"2026-09-21T00:00:00.000Z","score":0.0046,"percentile":null},{"date":"2026-09-22T00:00:00.000Z","score":0.0046,"percentile":null},{"date":"2026-09-23T00:00:00.000Z","score":0.0046,"percentile":null},{"date":"2026-09-24T00:00:00.000Z","score":0.0046,"percentile":null},{"date":"2026-09-25T00:00:00.000Z","score":0.0046,"percentile":null},{"date":"2026-09-26T00:00:00.000Z","score":0.0046,"percentile":null},{"date":"2026-09-27T00:00:00.000Z","score":0.0046,"percentile":null},{"date":"2026-09-28T00:00:00.000Z","score":0.0046,"percentile":null},{"date":"2026-09-29T00:00:00.000Z","score":0.0046,"percentile":null},{"date":"2026-09-30T00:00:00.000Z","score":0.0046,"percentile":null},{"date":"2026-10-01T00:00:00.000Z","score":0.0046,"percentile":null},{"date":"2026-10-02T00:00:00.000Z","score":0.0046,"percentile":null},{"date":"2026-10-03T00:00:00.000Z","score":0.0046,"percentile":null},{"date":"2026-10-04T00:00:00.000Z","score":0.0046,"percentile":null},{"date":"2026-10-05T00:00:00.000Z","score":0.0046,"percentile":null},{"date":"2026-10-06T00:00:00.000Z","score":0.0046,"percentile":null},{"date":"2026-10-07T00:00:00.000Z","score":0.0046,"percentile":null},{"date":"2026-10-08T00:00:00.000Z","score":0.0046,"percentile":null},{"date":"2026-10-09T00:00:00.000Z","score":0.0046,"percentile":null},{"date":"2026-10-10T00:00:00.000Z","score":0.0046,"percentile":null},{"date":"2026-10-11T00:00:00.000Z","score":0.0046,"percentile":null},{"date":"2026-10-12T00:00:00.000Z","score":0.0046,"percentile":null},{"date":"2026-10-13T00:00:00.000Z","score":0.0046,"percentile":null},{"date":"2026-10-14T00:00:00.000Z","score":0.0046,"percentile":null},{"date":"2026-10-15T00:00:00.000Z","score":0.0046,"percentile":null},{"date":"2026-10-16T00:00:00.000Z","score":0.0046,"percentile":null},{"date":"2026-10-17T00:00:00.000Z","score":0.0046,"percentile":null},{"date":"2026-10-18T00:00:00.000Z","score":0.0046,"percentile":null},{"date":"2026-10-19T00:00:00.000Z","score":0.0046,"percentile":null},{"date":"2026-10-20T00:00:00.000Z","score":0.0046,"percentile":0.38589}]},"kev":{"state":"not-listed","entries":[],"listedCount":0,"totalCatalogs":3,"catalogs":[{"source":"cisa","label":"CISA","listed":false,"entry":null},{"source":"enisa","label":"ENISA","listed":false,"entry":null},{"source":"circl","label":"CIRCL","listed":false,"entry":null}]},"ransomware":{"state":"none-recorded","sources":[]},"exploits":[],"exploitCount":0,"weaknesses":[{"id":"CWE-400","name":"Uncontrolled Resource Consumption","description":"The product does not properly control the allocation and maintenance of a limited resource.","type":"weakness","status":"Draft","abstraction":"Class","likelihoodOfExploit":"High","url":"https://cwe.mitre.org/data/definitions/400.html"},{"id":"CWE-407","name":"Inefficient Algorithmic Complexity","description":"An algorithm in a product has an inefficient worst-case computational complexity that may be detrimental to system performance and can be triggered by an attacker, typically using crafted manipulations that ensure that the worst case is being reached.","type":"weakness","status":"Incomplete","abstraction":"Class","likelihoodOfExploit":"Low","url":"https://cwe.mitre.org/data/definitions/407.html"}],"affected":[{"vendor":"chainguard","product":"airflow-2","name":"airflow-2","label":"airflow-2","ecosystem":"Chainguard","cpePart":null,"purl":"pkg:apk/chainguard/airflow-2","purlType":"apk","versions":[{"text":"All versions","noFixRecorded":true,"fixedIn":null}],"versionsText":"All versions (No fix recorded)","eol":null,"hubHref":null},{"vendor":"chainguard","product":"airflow-3","name":"airflow-3","label":"airflow-3","ecosystem":"Chainguard","cpePart":null,"purl":"pkg:apk/chainguard/airflow-3","purlType":"apk","versions":[{"text":"< 3.2.2-r7","noFixRecorded":false,"fixedIn":null}],"versionsText":"< 3.2.2-r7","eol":null,"hubHref":null},{"vendor":"chainguard","product":"airflow-core-2","name":"airflow-core-2","label":"airflow-core-2","ecosystem":"Chainguard","cpePart":null,"purl":"pkg:apk/chainguard/airflow-core-2","purlType":"apk","versions":[{"text":"All versions","noFixRecorded":true,"fixedIn":null}],"versionsText":"All versions (No fix recorded)","eol":null,"hubHref":null},{"vendor":"chainguard","product":"airflow-core-3","name":"airflow-core-3","label":"airflow-core-3","ecosystem":"Chainguard","cpePart":null,"purl":"pkg:apk/chainguard/airflow-core-3","purlType":"apk","versions":[{"text":"< 3.2.2-r3","noFixRecorded":false,"fixedIn":null}],"versionsText":"< 3.2.2-r3","eol":null,"hubHref":null},{"vendor":"chainguard","product":"airflow-postgres-fips-3","name":"airflow-postgres-fips-3","label":"airflow-postgres-fips-3","ecosystem":"Chainguard","cpePart":null,"purl":"pkg:apk/chainguard/airflow-postgres-fips-3","purlType":"apk","versions":[{"text":"< 3.2.2-r1","noFixRecorded":false,"fixedIn":null}],"versionsText":"< 3.2.2-r1","eol":null,"hubHref":null},{"vendor":"chainguard","product":"litellm","name":"litellm","label":"litellm","ecosystem":"Chainguard","cpePart":null,"purl":"pkg:apk/chainguard/litellm","purlType":"apk","versions":[{"text":"< 1.89.0-r2","noFixRecorded":false,"fixedIn":null}],"versionsText":"< 1.89.0-r2","eol":null,"hubHref":null},{"vendor":"chainguard","product":"tritonserver-backend-vllm-cuda-12.9","name":"tritonserver-backend-vllm-cuda-12.9","label":"tritonserver-backend-vllm-cuda-12.9","ecosystem":"Chainguard","cpePart":null,"purl":"pkg:apk/chainguard/tritonserver-backend-vllm-cuda-12.9","purlType":"apk","versions":[{"text":"< 25.9.0_git20260617-r0","noFixRecorded":false,"fixedIn":null}],"versionsText":"< 25.9.0_git20260617-r0","eol":null,"hubHref":null},{"vendor":"chainguard","product":"wazuh-manager-framework","name":"wazuh-manager-framework","label":"wazuh-manager-framework","ecosystem":"Chainguard","cpePart":null,"purl":"pkg:apk/chainguard/wazuh-manager-framework","purlType":"apk","versions":[{"text":"< 4.14.5-r4","noFixRecorded":false,"fixedIn":null}],"versionsText":"< 4.14.5-r4","eol":null,"hubHref":null},{"vendor":"chainguard","product":"wazuh-manager-framework-fips","name":"wazuh-manager-framework-fips","label":"wazuh-manager-framework-fips","ecosystem":"Chainguard","cpePart":null,"purl":"pkg:apk/chainguard/wazuh-manager-framework-fips","purlType":"apk","versions":[{"text":"< 4.14.5-r4","noFixRecorded":false,"fixedIn":null}],"versionsText":"< 4.14.5-r4","eol":null,"hubHref":null},{"vendor":"wolfi","product":"airflow-3","name":"airflow-3","label":"airflow-3","ecosystem":"Wolfi","cpePart":null,"purl":"pkg:apk/wolfi/airflow-3","purlType":"apk","versions":[{"text":"< 3.2.2-r7","noFixRecorded":false,"fixedIn":null}],"versionsText":"< 3.2.2-r7","eol":null,"hubHref":null},{"vendor":"debian","product":"python-multipart","name":"python-multipart","label":"python-multipart","ecosystem":"Debian","cpePart":null,"purl":"pkg:deb/debian/python-multipart","purlType":"deb","versions":[{"text":"All versions","noFixRecorded":true,"fixedIn":null},{"text":"< 0.0.32-1","noFixRecorded":false,"fixedIn":null}],"versionsText":"All versions (No fix recorded) | < 0.0.32-1","eol":null,"hubHref":null},{"vendor":"ubuntu","product":"python-multipart","name":"python-multipart","label":"python-multipart","ecosystem":"Ubuntu","cpePart":null,"purl":"pkg:deb/ubuntu/python-multipart","purlType":"deb","versions":[{"text":"All versions","noFixRecorded":true,"fixedIn":null}],"versionsText":"All versions (No fix recorded)","eol":null,"hubHref":null},{"vendor":"fastapiexpert","product":"python-multipart","name":"python-multipart","label":"python-multipart","ecosystem":null,"cpePart":"a","purl":null,"purlType":null,"versions":[{"text":"< 0.0.30","noFixRecorded":false,"fixedIn":null}],"versionsText":"< 0.0.30","eol":null,"hubHref":"/vendor/fastapiexpert/python-multipart"},{"vendor":"kludex","product":"python-multipart","name":"python-multipart","label":"python-multipart","ecosystem":null,"cpePart":"a","purl":null,"purlType":null,"versions":[{"text":"< 0.0.30","noFixRecorded":false,"fixedIn":null}],"versionsText":"< 0.0.30","eol":null,"hubHref":"/vendor/kludex/python-multipart"},{"vendor":"PyPI","product":"python-multipart","name":"python-multipart","label":"python-multipart","ecosystem":"PyPI","cpePart":null,"purl":"pkg:pypi/python-multipart","purlType":"pypi","versions":[{"text":"< 0.0.30","noFixRecorded":false,"fixedIn":null}],"versionsText":"< 0.0.30","eol":null,"hubHref":null}],"affectedCount":15,"eol":{"hasEol":false,"count":0},"references":[{"url":"https://github.com/Kludex/python-multipart/security/advisories/GHSA-5rvq-cxj2-64vf","label":"github.com/Kludex/python-multipart/security/advisories/GHSA-5rvq-cxj2-64vf","hostname":"github.com","tags":["X Refsource CONFIRM","WEB","Advisory","Vendor Advisory"]},{"url":"https://github.com/Kludex/python-multipart","label":"github.com/Kludex/python-multipart","hostname":"github.com","tags":["PACKAGE"]},{"url":"https://pypi.org/project/python-multipart","label":"pypi.org/project/python-multipart","hostname":"pypi.org","tags":["PACKAGE"]},{"url":"https://github.com/advisories/GHSA-5rvq-cxj2-64vf","label":"github.com/advisories/GHSA-5rvq-cxj2-64vf","hostname":"github.com","tags":["Advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-53539","label":"nvd.nist.gov/vuln/detail/CVE-2026-53539","hostname":"nvd.nist.gov","tags":["Advisory"]},{"url":"https://ubuntu.com/security/CVE-2026-53539","label":"ubuntu.com/security/CVE-2026-53539","hostname":"ubuntu.com","tags":["REPORT"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-53539","label":"www.cve.org/CVERecord?id=CVE-2026-53539","hostname":"www.cve.org","tags":["REPORT"]},{"url":"https://security-tracker.debian.org/tracker/CVE-2026-53539","label":"security-tracker.debian.org/tracker/CVE-2026-53539","hostname":"security-tracker.debian.org","tags":["Advisory"]},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53539.json","label":"github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53539.json","hostname":"github.com","tags":["Advisory"]}],"lineage":{"upstream":[],"downstream":["OPENSUSE-SU-2026:21066-1","SUSE-SU-2026:22372-1"],"duplicates":[],"related":["CGA-2FJG-J4JJ-X26W","OPENSUSE-SU-2026:21066-1","SUSE-SU-2026:22372-1"]},"timeline":[{"kind":"published","date":"2026-06-22T16:55:42.787Z","label":"Published","detail":"Vulnerability first disclosed.","source":null},{"kind":"modified","date":"2026-06-23T16:08:36.474Z","label":"Last modified","detail":"Vulnerability information updated.","source":null}],"risk":{"score":30,"level":"medium","profile":"Default","thresholds":{"critical":75,"high":50,"medium":25,"low":10}},"meta":{"dataAsOf":"2026-10-20T21:18:53.244Z","stale":false,"partial":false}}