CVE-2026-47072 — Security Box Score

CVE · referencelatest edition

Reference page — cumulative record through Wednesday, August 19, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.

CVE-2026-47072MEDIUM

benoitc hackney — CRLF injection in WebSocket upgrade request in hackney

  AV  AC  AT  PR  UI  VC  VI  VA   CVSS    EPSS   %ile   KEV
   N   L   P   N   N   N   L   N    6.9   .0054   43.2     —

AFFECTED
  Product  Versions                                    Fixed
  hackney  2.0.0 –                                     —
  hackney  690cecaf236fba49526da404a5bc889a24367a3e –  —

TIMELINE
  May 18  Reserved by EEF
  May 25  EXPLOIT PUBLISHED — CVE-2026-47072 (benoitc hackney). Public exploit reference added.
  May 25  Published (CNA: EEF)

CWE-93 · CNA: EEF · CVSS v4.0 · 4 references · NVD status: Analyzed

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.

Lifecycle

Complete event history — 3 events, chronological
Date	Event	Detail
May 18, 2026	Reserved	Reserved by EEF
May 25, 2026	EXPLOIT PUBLISHED	EXPLOIT PUBLISHED — CVE-2026-47072 (benoitc hackney). Public exploit reference added.
May 25, 2026	Published	Published (CNA: EEF)

Affected

Affected products and packages — 2 rows
Vendor	Product / Package	Ecosystem	Version introduced	Fixed
benoitc	hackney	—	2.0.0	—
benoitc	hackney	—	690cecaf236fba49526da404a5bc889a24367a3e	—

Weaknesses

CWE-93

References (4)

https://cna.erlef.org/cves/CVE-2026-47072.html [Patch, Third Party Advisory]
https://github.com/benoitc/hackney/commit/52310ca807e7b48441ba0e9129171f535313fdd1 [Patch]
https://github.com/benoitc/hackney/security/advisories/GHSA-f9vr-g2g2-x9fg [Exploit, Patch, Vendor Advisory]
https://osv.dev/vulnerability/EEF-CVE-2026-47072 [Patch, Third Party Advisory]

Authoritative record: CVE-2026-47072 at cve.org

Vendors: benoitc

Weaknesses: CWE-93

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-47072 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Wednesday, August 19, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.