Description
Improper Neutralization of CRLF Sequences ('CRLF Injection') vulnerability in benoitc hackney allows HTTP Response Splitting. The hackney_cookie:setcookie/3 function in src/hackney_cookie.erl validates the Name and Value arguments against CRLF and control characters, but concatenates the domain and path options verbatim into the output iolist with no equivalent check. An attacker who controls either option — for example by supplying a Host header value forwarded as the cookie domain, or a request path forwarded as the cookie path — can inject a literal CRLF sequence and arbitrary additional Set-Cookie headers into the HTTP response. This issue affects hackney: from 0.9.0 before 4.0.1.
Problem types
CWE-93 Improper Neutralization of CRLF Sequences ('CRLF Injection')
Product status
0.9.0 (semver) before 4.0.1
602d5c7f2ea4acbc83ed75230655d935a0750ebc (git) before 8e02b99c28aea1b3fa2ddc0e66f51fe5bb0ac540
Credits
Peter Ullrich
Benoit Chesneau
Jonatan Männchen / EEF
References
github.com/...ackney/security/advisories/GHSA-mp55-p8c9-rfw2
github.com/...ackney/security/advisories/GHSA-mp55-p8c9-rfw2
cna.erlef.org/cves/CVE-2026-47069.html
osv.dev/vulnerability/EEF-CVE-2026-47069
github.com/...ommit/8e02b99c28aea1b3fa2ddc0e66f51fe5bb0ac540