CVE-2026-47069

CRLF injection in cookie domain/path options in hackney

MEDIUM
5.3
CVSS Score
Published: May 25, 2026 at 02:00 PM UTC
Updated: July 24, 2026 at 10:23 AM UTC
1 product affected across 1 vendorHackney

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Severity
MEDIUM5.3
Exploit prediction
EPSS 0.4%
SSVC
PoC

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

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

0.9.0 ≤ v < 4.0.10.9.0602d5c7f2ea4acbc83ed75230655d935a0750ebc
Vendor states this is fixed in 8e02b99c28aea1b3fa2ddc0e66f51fe5bb0ac540 (fixed)
Affected range stops below 4.0.1, so it looks safe — our inference, not a vendor statement

References (4)

Vendor AdvisoryRelatedExploitPatch
Source: cverecord
https://github.com/benoitc/hackney/security/advisories/GHSA-mp55-p8c9-rfw2
RelatedPatchThird Party Advisory
Source: cverecord
https://cna.erlef.org/cves/CVE-2026-47069.html
RelatedPatchThird Party Advisory
Source: cverecord
https://osv.dev/vulnerability/EEF-CVE-2026-47069

SSVC — Action Prioritization

SSVCPoCNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
LOW
Availability
NONE
Vector?

Quick Info

StatusANALYZED
CWE
CWE-93

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