{"id":"CVE-2026-8161","aliases":["CLSA-2026-1784682964","DEBIAN-CVE-2026-8161","EUVD-2026-29440","GHSA-qxch-whhj-8956","ROOT-APP-NPM-CVE-2026-8161","UBUNTU-CVE-2026-8161"],"status":"published","title":"multiparty vulnerable to Denial of Service via Prototype Pollution leading to Uncaught Exception","description":"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.","severity":{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-09","score":0.00473,"percentile":0.4118,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":true,"fix_available":true},"cwes":["CWE-1321","CWE-248"],"published":"2026-05-12T08:50:37Z","modified":"2026-10-28T02:30:27Z","exploits":[{"source":"pocgithub","id":"Ser0n-ath/multiparty-CVE-2026-8161","title":"Ser0n-ath/multiparty-CVE-2026-8161","date":"2026-05-11","url":"https://github.com/Ser0n-ath/multiparty-CVE-2026-8161"}],"fixes":[{"ecosystem":"npm","package":"multiparty","fixed_in":["4.3.0"],"sources":["ghsa","osv"]},{"ecosystem":"Debian:14","package":"node-multiparty","fixed_in":["4.3.0-1"],"sources":["osv"]},{"ecosystem":"Root:npm","package":"@rootio/multiparty","fixed_in":["3.3.2-root.io.1"],"sources":["osv"]},{"ecosystem":"Root:npm","package":"multiparty","fixed_in":["3.3.2-aikido.1"],"sources":["osv"]}],"affected":[{"source":"ghsa","ecosystem":"npm","package":"multiparty","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"4.2.3"},{"fixed":"4.3.0"}]}]},{"source":"osv","ecosystem":"TuxCare:npm","package":"multiparty","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"3.3.2-tuxcare.0"},{"fixed":"3.3.2-tuxcare.1"}]}],"versions":["3.3.2"],"bundled":3},{"source":"osv","ecosystem":"Debian:12","package":"node-multiparty","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.2.3-2","4.2.3-3","4.2.3-4","4.2.3-5","4.3.0+~4.2.1-1","4.3.0-1","4.3.1+~4.2.1-1"]},{"source":"osv","ecosystem":"Debian:13","package":"node-multiparty","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.2.3-3","4.2.3-4","4.2.3-5","4.3.0+~4.2.1-1","4.3.0-1","4.3.1+~4.2.1-1"]},{"source":"osv","ecosystem":"Debian:14","package":"node-multiparty","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.3.0-1"}]}],"versions":["4.2.3-3","4.2.3-4","4.2.3-5"]},{"source":"osv","ecosystem":"npm","package":"multiparty","ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"4.3.0"}]}]},{"source":"osv","ecosystem":"Root:npm","package":"@rootio/multiparty","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.3.2-root.io.1"}]}]},{"source":"osv","ecosystem":"Root:npm","package":"multiparty","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.3.2-aikido.1"}]}]},{"source":"osv","ecosystem":"Ubuntu:16.04:LTS","package":"node-multiparty","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.0.0-1"]},{"source":"osv","ecosystem":"Ubuntu:18.04:LTS","package":"node-multiparty","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.0.0-1","4.0.0-1ubuntu1"]},{"source":"osv","ecosystem":"Ubuntu:20.04:LTS","package":"node-multiparty","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.2.1-1","4.2.1-2"]},{"source":"osv","ecosystem":"Ubuntu:22.04:LTS","package":"node-multiparty","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.2.2-2","4.2.2-3"]},{"source":"osv","ecosystem":"Ubuntu:24.04:LTS","package":"node-multiparty","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.2.3-2"]},{"source":"osv","ecosystem":"Ubuntu:25.10","package":"node-multiparty","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.2.3-2","4.2.3-3"]},{"source":"osv","ecosystem":"Ubuntu:26.10","package":"node-multiparty","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.2.3-5","4.3.0+~4.2.1-1"]},{"source":"osv","ecosystem":"Ubuntu:26.04:LTS","package":"node-multiparty","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.2.3-3","4.2.3-4build1","4.2.3-5"]}],"products":[{"vendor":"multiparty","product":"multiparty"},{"vendor":"pillarjs","product":"multiparty"}],"references":[{"url":"https://github.com/pillarjs/multiparty/security/advisories/GHSA-qxch-whhj-8956","tags":["Vendor Advisory","advisory","web","report"]},{"url":"https://cna.openjsf.org/security-advisories.html","tags":["Third Party Advisory","advisory","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-8161","tags":["advisory"]},{"url":"https://github.com/pillarjs/multiparty/releases/tag/v4.3.0","tags":["web"]},{"url":"https://github.com/advisories/GHSA-qxch-whhj-8956"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/8xxx/CVE-2026-8161.json","tags":["advisory"]},{"url":"https://security-tracker.debian.org/tracker/CVE-2026-8161","tags":["advisory"]},{"url":"https://github.com/pillarjs/multiparty","tags":["package"]},{"url":"https://ubuntu.com/security/CVE-2026-8161","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-8161","tags":["report"]}],"sources":{"cve":[{"id":"CVE-2026-8161","title":"multiparty vulnerable to Denial of Service via Prototype Pollution leading to Uncaught Exception","description":"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.","status":"published","published":"2026-05-12T08:50:37.685Z","modified":"2026-05-12T12:32:10.127Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"cna"}],"cwes":["CWE-248","CWE-1321"],"updated_at":"2026-11-02T13:48:02.226896Z"}],"euvd":[{"id":"EUVD-2026-29440","description":"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.","status":"published","published":"2026-05-12T08:50:37Z","modified":"2026-05-12T12:32:10Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"updated_at":"2026-11-02T19:04:37.66514Z"}],"ghsa":[{"id":"GHSA-qxch-whhj-8956","title":"multiparty: Denial of Service via Prototype Pollution leads to Uncaught Exception","description":"### Impact\n\nmultiparty@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 (e.g., `__proto__`, `constructor`, `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. Any service accepting multipart uploads via multiparty is affected.\n\n### Patches\n\nUsers should upgrade to multiparty@4.3.0 or higher.\n\n### Workarounds\n\nNone.","status":"published","published":"2026-05-18T17:35:01Z","modified":"2026-05-18T17:35:02Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"cwes":["CWE-248","CWE-1321"],"updated_at":"2026-11-02T14:40:11.298154Z"}],"nvd":[{"id":"CVE-2026-8161","description":"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.","status":"published","published":"2026-05-12T10:16:48.987Z","modified":"2026-06-17T11:03:34.383Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"secondary"}],"cwes":["CWE-248","CWE-1321"],"updated_at":"2026-11-02T14:12:18.613259Z"}],"osv":[{"id":"CVE-2026-8161","title":"multiparty vulnerable to Denial of Service via Prototype Pollution leading to Uncaught Exception","description":"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.","status":"published","published":"2026-05-12T08:50:37.685Z","modified":"2026-10-28T02:30:27.455134991Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"cwes":["CWE-1321","CWE-248"],"updated_at":"2026-11-02T15:45:18.131258Z"},{"id":"DEBIAN-CVE-2026-8161","description":"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.","status":"published","published":"2026-05-12T10:16:48.987Z","modified":"2026-10-01T03:03:51.543484589Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"updated_at":"2026-11-02T15:46:04.577397Z"},{"id":"GHSA-qxch-whhj-8956","title":"multiparty: Denial of Service via Prototype Pollution leads to Uncaught Exception","description":"### Impact\n\nmultiparty@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 (e.g., `__proto__`, `constructor`, `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. Any service accepting multipart uploads via multiparty is affected.\n\n### Patches\n\nUsers should upgrade to multiparty@4.3.0 or higher.\n\n### Workarounds\n\nNone.","status":"published","published":"2026-05-18T17:35:01Z","modified":"2026-05-18T17:56:25.505915Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"cwes":["CWE-1321","CWE-248"],"updated_at":"2026-11-02T15:46:55.122811Z"},{"id":"UBUNTU-CVE-2026-8161","description":"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.","status":"published","published":"2026-05-12T10:16:00Z","modified":"2026-10-17T13:01:10.826121435Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"updated_at":"2026-11-02T16:57:22.213888Z"},{"id":"CLSA-2026-1784682964","title":"TuxCare security update for multiparty (3 CVEs)","description":"TuxCare rebuilt multiparty to address 3 CVEs. Fixed in 3.3.2-tuxcare.1.","status":"published","published":"2026-08-04T14:52:46Z","modified":"2026-10-15T09:47:54.13807981Z","updated_at":"2026-11-02T15:43:46.482572Z"},{"id":"ROOT-APP-NPM-CVE-2026-8161","title":"CVE-2026-8161 in @rootio/multiparty - Patched by Root","description":"Root has patched CVE-2026-8161 in the @rootio/multiparty package for Root:npm. Multiple fixed versions available.","status":"published","published":"2026-07-14T13:51:17Z","modified":"2026-07-14T19:22:02.259123217Z","updated_at":"2026-11-02T15:53:27.649662Z"}]}}