PT-2026-43071 · Benoitc · Hackney

Benoit Chesneau + 2 · Published 2026-05-25 · Updated 2026-05-25 · CVE-2026-47075

Mitre

CVSS v4.0

6.8

Medium

Base vector

AV:L/AC:L/AT:P/PR:N/UI:A/VC:N/VI:H/VA:N/SC:N/SI:H/SA:N

Improper Neutralization of CRLF Sequences vulnerability in benoitc hackney allows HTTP Request Splitting. hackney does not percent-encode carriage return (r) or line feed ( ) characters in the URL query component before constructing the HTTP/1.1 request target. Characters outside the grammar defined in RFC 3986 Section 3.4 must be percent-encoded, but hackney url:make url/3 passes the query binary directly without validation or escaping. An attacker who can control all or part of a URL passed to hackney can inject raw CRLF sequences into the query string, which are then sent as HTTP line breaks in the request target. This enables injection of arbitrary HTTP headers or splitting of the HTTP request.

This issue affects hackney: from 0 before 4.0.1.

Fix

Weakness Enumeration

CWE-93

Related Identifiers

CVE-2026-47075

Affected Products

Hackney

References · 4

• https://github.com/benoitc/hackney/commit/ca73dd0aba0ed557449c18288bf07241671a43c9 · Patch
• https://github.com/benoitc/hackney/security/advisories/GHSA-j9wq-vxxc-94wf · Vendor Advisory
• https://osv.dev/vulnerability/EEF-CVE-2026-47075 · Note
• https://cna.erlef.org/cves/CVE-2026-47075.html · Note