CVE-2026-47072

7.5 HIGH
Published: May 25, 2026 Modified: May 28, 2026
View on NVD

Description

Improper Neutralization of CRLF Sequences ('CRLF Injection') vulnerability in benoitc hackney allows HTTP Request/Response Splitting. The WebSocket upgrade code in src/hackney_ws.erl copies the host, path, headers (ExtraHeaders), and protocols options from the caller-supplied opts map into the internal #ws_data{} record in init/1 and then splices them verbatim into the raw HTTP/1.1 upgrade request by binary concatenation in do_handshake/1. No CRLF or NUL stripping is performed at any of these four injection sites. An attacker who controls any of these options — for example by forwarding URL components or header values from untrusted input into hackney_ws:start_link/1 — can inject arbitrary HTTP headers into the outbound WebSocket upgrade request, leading to header injection, credential spoofing toward the upstream server, log and cache poisoning, or request smuggling via intermediary proxies. This issue affects hackney: from 2.0.0 before 4.0.1.

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CVSS v3.x Details

0.0 Low Medium High Critical 10.0
Vector String
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

References to Advisories, Solutions, and Tools

Patch Vendor Advisory Exploit Third Party Advisory
https://cna.erlef.org/cves/CVE-2026-47072.html
Source: 6b3ad84c-e1a6-4bf7-a703-f496b71e49db
Patch Third Party Advisory
https://github.com/benoitc/hackney/security/advisories/GHSA-f9vr-g2g2-x9fg
Source: 6b3ad84c-e1a6-4bf7-a703-f496b71e49db
Exploit Patch Vendor Advisory
https://osv.dev/vulnerability/EEF-CVE-2026-47072
Source: 6b3ad84c-e1a6-4bf7-a703-f496b71e49db
Patch Third Party Advisory
https://github.com/benoitc/hackney/security/advisories/GHSA-f9vr-g2g2-x9fg
Source: 134c704f-9b21-4f2e-91b3-4a467353bcc0
Exploit Patch Vendor Advisory

5 reference(s) from NVD

Quick Stats

CVSS v3 Score
7.5 / 10.0
EPSS (Exploit Probability)
0.5%
38th percentile
Exploitation Status
Not in CISA KEV

Weaknesses (CWE)

Affected Vendors

benoitc