CVE-2026-47069 CRLF injection in cookie domain/path options in hackney
Attackers can inject CRLF sequences into cookie domain or path options, enabling HTTP response splitting and header injection in applications using hackney.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-47069?
CVE-2026-47069 is a low-severity vulnerability in benoitc hackney, published on 25 May 2026. It can only be exploited from the same machine or local network, with no action from the victim.
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.
Weakness: CWE-93
Which versions are affected by CVE-2026-47069?
3 open source packages ship an affected version, including hackney. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
hackney Hex | From 0.9.0 | 4.0.1 |
hackney Hex | From 0.9.0 | 4.0.1 |
hackney Hex | From 0.9.0 | 4.0.1 |
Products include Benoitc Hackney.
How do I fix CVE-2026-47069?
Upgrade hackney to 4.0.1 or later.
Is CVE-2026-47069 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-47069 exists.
Other vulnerabilities in benoitc hackney
- CVE-2026-47066 Infinite loop in Alt-Svc header parser in hackney
- CVE-2026-47067 Atom table exhaustion via unrecognized URL schemes in hackney
- CVE-2026-47073 Unbounded memory consumption in WebSocket client in hackney
- CVE-2026-47071 SOCKS5 TLS upgrade ignores caller timeout in hackney
- CVE-2026-47077 Unbounded body accumulation in HTTP/3 response loop in hackney
Sources
Also known as EEF-CVE-2026-47069, GHSA-mp55-p8c9-rfw2.