{"id":"CVE-2026-8161","summary":"multiparty vulnerable to Denial of Service via Prototype Pollution leading to Uncaught Exception","details":"multiparty@4.2.3 and lower versions are vulnerable to denial of service via uncaught exception. By sending a multipart/form-data request with a field name that collides with an inherited Object.prototype property such as __proto__, constructor, or toString, the parser invokes .push() on the inherited prototype value rather than an array, throwing a TypeError that propagates as an uncaught exception and crashes the process. Impact: any service accepting multipart uploads via multiparty is affected. Workarounds: none. Upgrade to multiparty@4.3.0 or higher.","aliases":["GHSA-qxch-whhj-8956"],"modified":"2026-07-08T08:12:41.261572762Z","published":"2026-05-12T08:50:37.685Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/8xxx/CVE-2026-8161.json","cna_assigner":"openjs","cwe_ids":["CWE-1321","CWE-248"]},"references":[{"type":"ADVISORY","url":"https://cna.openjsf.org/security-advisories.html"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/8xxx/CVE-2026-8161.json"},{"type":"ADVISORY","url":"https://github.com/pillarjs/multiparty/security/advisories/GHSA-qxch-whhj-8956"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-8161"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/pillarjs/multiparty","events":[{"introduced":"0"},{"fixed":"f7963dbfb8c66764790790cf79eb0992c0e45ff0"}],"database_specific":{"source":["AFFECTED_FIELD","CPE_RANGE"],"extracted_events":[{"introduced":"0"},{"last_affected":"4.2.3"},{"fixed":"4.3.0"}],"cpe":"cpe:2.3:a:pillarjs:multiparty:*:*:*:*:*:node.js:*:*"}}],"versions":["4.2.3","4.2.2","4.2.1","4.2.0","4.1.4","4.1.3","4.1.2","4.1.1","4.1.0","4.0.0","3.3.2","3.3.1","3.3.0","3.2.9","3.2.8","3.2.7","3.2.6","3.2.5","3.2.4","3.2.2","3.2.3","3.2.1","3.2.0","3.1.2","3.1.1","3.1.0","3.0.0","2.2.0","2.1.9","2.1.8","2.1.7","2.1.6","2.1.5","2.1.4","2.1.3","2.1.2","2.1.1","2.1.0","2.0.0","v1.0.11","v1.0.10","v1.0.9","v1.0.8","v1.0.7","v1.0.6","v1.0.5","v1.0.4","v1.0.3","v1.0.2","v1.0.1","v1.0.0","v0.9.11","v0.9.10","v0.9.9","v0.9.8","v0.9.7","v0.9.6","v0.9.5","v0.9.4","v0.9.3","v0.9.2","v0.9.1","v0.9.0","v0.8.0","v0.7.0","v0.6.0","v0.5.0","v0.4.0","v0.3.0","v0.2.0","v0.1.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-8161.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"}]}