PT-2026-43069 · Hackney · Hackney
Benoit Chesneau
+2
·
Published
2026-05-25
·
Updated
2026-06-26
·
CVE-2026-47072
CVSS v3.1
7.5
High
| Vector | AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N |
Name of the Vulnerable Software and Affected Versions
hackney versions 2.0.0 through 4.0.0
Description
Improper Neutralization of CRLF Sequences, also known as CRLF Injection, allows HTTP Request/Response Splitting. The WebSocket upgrade code in
src/hackney ws.erl copies the host, path, headers (ExtraHeaders), and protocols options from the caller-supplied opts map into the internal #ws data{} record in init/1 and then splices them verbatim into the raw HTTP/1.1 upgrade request by binary concatenation in do handshake/1. Because no CRLF or NUL stripping is performed at these four injection sites, an attacker controlling these options—such as by forwarding URL components or header values from untrusted input into hackney ws:start link/1—can inject arbitrary HTTP headers into the outbound WebSocket upgrade request. This can lead to header injection, credential spoofing toward the upstream server, log and cache poisoning, or request smuggling via intermediary proxies.Recommendations
Update to version 4.0.1.
Exploit
Fix
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Weakness Enumeration
Related Identifiers
Affected Products
Hackney