CRLF Injection Affecting form-data package, versions <2.5.6>=3.0.0 <3.0.5>=4.0.0 <4.0.6
Threat Intelligence
Snyk has a proof-of-concept or detailed explanation of how to exploit this vulnerability.
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-JS-FORMDATA-17337015
- published14 Jun 2026
- disclosed12 Jun 2026
- creditYue (Knox) Liu
Introduced: 12 Jun 2026
NewCVE-2026-12143 (opens in a new tab)How to fix?
Upgrade form-data to version 2.5.6, 3.0.5, 4.0.6 or higher.
Overview
Affected versions of this package are vulnerable to CRLF Injection via the _multiPartHeader function when untrusted input is provided via field or filename to FormData#append. An attacker can inject additional headers or multipart parts by including carriage returns, line feeds, or double quotes in the input. This can allow the modification or addition of form fields visible to downstream parsers.
PoC
const FormData = require('form-data');
const form = new FormData();
form.append('email"\r\nX-Injected: true\r\nfake="', 'user@example.com');
console.log(form.getBuffer().toString());