CVE-2026-47075 Details
Description
Improper Neutralization of CRLF Sequences vulnerability in benoitc hackney allows HTTP Request Splitting. hackney does not percent-encode carriage return (\r) or line feed (\n) characters in the URL query component before constructing the HTTP/1.1 request target. Characters outside the grammar defined in RFC 3986 Section 3.4 must be percent-encoded, but hackney_url:make_url/3 passes the query binary directly without validation or escaping. An attacker who can control all or part of a URL passed to hackney can inject raw CRLF sequences into the query string, which are then sent as HTTP line breaks in the request target. This enables injection of arbitrary HTTP headers or splitting of the HTTP request. This issue affects hackney: from 0.13.1 before 4.0.1.
A CRLF injection vulnerability has been identified in the benoitc hackney HTTP client library for Erlang. This issue allows HTTP request splitting by improperly handling carriage return and line feed characters in the URL query component. Before version 4.0.1, hackney's URL construction did not percent-encode these characters as required by RFC 3986, enabling attackers to inject raw CRLF sequences. When the request is sent, these sequences are interpreted as line breaks, facilitating the injection of arbitrary HTTP headers or splitting the request into two.
Users can upgrade to hackney version 4.0.1 or later, where this vulnerability has been fixed.
Metrics
CVSS 4.0 Severity and Vector Strings:
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
CISA-ADP
Assessed May 26, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/benoitc/hackney/security/advisories/GHSA-j9wq-vxxc-94wf | CISA-ADP | ExploitPatchVendor Advisory |
| https://cna.erlef.org/cves/CVE-2026-47075.html | EEF | PatchThird Party Advisory |
| https://github.com/benoitc/hackney/commit/ca73dd0aba0ed557449c18288bf07241671a43c9 | EEF | Patch |
| https://github.com/benoitc/hackney/security/advisories/GHSA-j9wq-vxxc-94wf | EEF | ExploitPatchVendor Advisory |
| https://osv.dev/vulnerability/EEF-CVE-2026-47075 | EEF | PatchThird Party Advisory |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-93 | Improper Neutralization of CRLF Sequences ('CRLF Injection') | EEF |
Affected Products
| Product | Versions |
|---|---|
| benoitc hackney | < 4.0.1 |
CPE
Remediation
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Change History
7 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jul 24, 2026 | CVE Modified | EEF |
| Jul 24, 2026 | CVE Translated | [email protected] |
| Jun 17, 2026 | CVE Modified | CISA-ADP |
| Jun 17, 2026 | CVE Modified | EEF |
| May 28, 2026 | Initial Analysis | [email protected] |
| May 26, 2026 | CVE Modified | CISA-ADP |
| May 25, 2026 | New CVE Received | EEF |