Vulnerability · Published May 25, 2026 · Assigned by EEF
CVE-2026-47069CRLF injection in cookie domain/path options in hackney
Low 2.1
In plain English
A low-severity security flaw in hackney from benoitc. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 37% of all known vulnerabilities).
Official 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.
Affected products (as reported)
Weakness: CWE-93 · Vector: CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:L/SA:N