# 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.

- **Severity:** Low 2.1 (`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`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 25 May 2026
- **Updated:** 27 May 2026
- **Also known as:** EEF-CVE-2026-47069, GHSA-mp55-p8c9-rfw2

## 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 (Improper Neutralization of CRLF Sequences)

## Which versions are affected by CVE-2026-47069?

3 open source packages ship an affected version, including hackney. It affects 1 product.


| Package | Ecosystem | 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: 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](https://insights.sbomify.com/CVE-2026-47066/): Infinite loop in Alt-Svc header parser in hackney (high 8.7)
- [CVE-2026-47067](https://insights.sbomify.com/CVE-2026-47067/): Atom table exhaustion via unrecognized URL schemes in hackney (high 8.7)
- [CVE-2026-47073](https://insights.sbomify.com/CVE-2026-47073/): Unbounded memory consumption in WebSocket client in hackney (high 8.7)
- [CVE-2026-47071](https://insights.sbomify.com/CVE-2026-47071/): SOCKS5 TLS upgrade ignores caller timeout in hackney (high 8.2)
- [CVE-2026-47077](https://insights.sbomify.com/CVE-2026-47077/): Unbounded body accumulation in HTTP/3 response loop in hackney (high 8.2)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-47069 and fix it if it is affected.

What it is: 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.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-47069 exists.

Affected packages and fixed versions:
- hackney (Hex): affected from 0.9.0; fixed in 4.0.1
- hackney (Hex): affected from 0.9.0; fixed in 4.0.1
- hackney (Hex): affected from 0.9.0; fixed in 4.0.1

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-47069/ (Markdown: https://insights.sbomify.com/CVE-2026-47069/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-47069
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-47069
- OSV: https://osv.dev/vulnerability/CVE-2026-47069

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-47069/
Summaries are generated and may contain mistakes; the official description above is the record.