CRLF injection in cookie domain/path options in hackney

Summary

CVECVE-2026-47069
StatePUBLISHED
AssignerEEF
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-05-25 15:16:21 UTC
Updated2026-05-27 13:53:28 UTC
DescriptionImproper 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.

Risk And Classification

Primary CVSS: v4.0 2.1 LOW from 6b3ad84c-e1a6-4bf7-a703-f496b71e49db

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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS: 0.000210000 probability, percentile 0.062780000 (date 2026-05-27)

Problem Types: CWE-93 | CWE-93 CWE-93 Improper Neutralization of CRLF Sequences ('CRLF Injection')


VersionSourceTypeScoreSeverityVector
4.06b3ad84c-e1a6-4bf7-a703-f496b71e49dbSecondary2.1LOWCVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:L/SA:N/E:X/C...
4.0CNACVSS2.1LOWCVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:L/SA:N
3.1[email protected]Primary5.3MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

CVSS v4.0 Breakdown

Attack Vector
Local
Attack Complexity
Low
Attack Requirements
Present
Privileges Required
None
User Interaction
None
Confidentiality
None
Integrity
Low
Availability
None
Sub Conf.
None
Sub Integrity
Low
Sub Availability
None

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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
Low
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

NVD Known Affected Configurations (CPE 2.3)

TypeVendorProductVersionUpdateEditionLanguage
Application Benoitc Hackney All All All All

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Benoitc Hackney affected 0.9.0 4.0.1 semver Not specified
CNA Benoitc Hackney affected 602d5c7f2ea4acbc83ed75230655d935a0750ebc 8e02b99c28aea1b3fa2ddc0e66f51fe5bb0ac540 git Not specified

References

ReferenceSourceLinkTags
cna.erlef.org/cves/CVE-2026-47069.html 6b3ad84c-e1a6-4bf7-a703-f496b71e49db cna.erlef.org Third Party Advisory, Patch
osv.dev/vulnerability/EEF-CVE-2026-47069 6b3ad84c-e1a6-4bf7-a703-f496b71e49db osv.dev Third Party Advisory, Patch
github.com/benoitc/hackney/security/advisories/GHSA-mp55-p8c9-rfw2 134c704f-9b21-4f2e-91b3-4a467353bcc0 github.com Exploit, Patch, Vendor Advisory
github.com/benoitc/hackney/commit/8e02b99c28aea1b3fa2ddc0e66f51fe5bb0ac540 6b3ad84c-e1a6-4bf7-a703-f496b71e49db github.com Patch
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Vendor Comments And Credit

Discovery Credit

CNA: Peter Ullrich (en)

CNA: Benoit Chesneau (en)

CNA: Jonatan Männchen (en)

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