CRLF Injection Affecting hackney package, versions <4.0.1
Threat Intelligence
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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-HEX-HACKNEY-16877752
- published26 May 2026
- disclosed25 May 2026
- creditUnknown
Introduced: 25 May 2026
CVE-2026-47075 (opens in a new tab)How to fix?
Upgrade hackney to version 4.0.1 or higher.
Overview
Affected versions of this package are vulnerable to CRLF Injection via the request, request_streaming, send_headers, and request_async entry points in hackney_conn. An attacker can inject extra header lines or split the HTTP request by supplying a path or query string containing raw CR, LF, or NUL bytes. This lets a caller-controlled URL corrupt the outbound request sent by the client, enabling header injection and request splitting against servers that receive the traffic.