What’s Vulnerable › Vulnerabilities

CVE-2026-47069: CRLF injection in cookie domain/path options in hackney

• Severity: medium (CVSS 5.3 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2026-05-25 · updated 2026-07-24
• Weakness: CWE-93

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

• benoitc hackney: from 0.9.0 before 4.0.1 — fixed in 4.0.1

How to fix

Upgrade to a fixed version: benoitc hackney 4.0.1. Check the vendor advisory for mitigations.

References

• https://cna.erlef.org/cves/CVE-2026-47069.html
• https://github.com/benoitc/hackney/commit/8e02b99c28aea1b3fa2ddc0e66f51fe5bb0ac540
• https://github.com/benoitc/hackney/security/advisories/GHSA-mp55-p8c9-rfw2
• https://osv.dev/vulnerability/EEF-CVE-2026-47069
• https://github.com/benoitc/hackney/security/advisories/GHSA-mp55-p8c9-rfw2

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