Vulnerability in Benoitc Hackney

CVE-2026-47069

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.

Vulnerability class: CRLF Injection

Published · last modified .

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N.

EPSS exploit prediction

EPSS: 0.004 (28.8th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 29th percentile — 28.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-47069: held from 0.004 to 0.004.

EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: -0.001

Affected products

  • Benoitc Hackney — versions 0.9.0, 602d5c7f2ea4acbc83ed75230655d935a0750ebc

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-47069?
CVE-2026-47069 is a medium-severity vulnerability in Benoitc Hackney, classified under CRLF Injection. CVSS score: 5.3/10. Published 2026-05-25.
How severe is CVE-2026-47069?
Medium severity. CVSS v3 base score is 5.3 out of 10.