Vulnerability in hackney (CVE-2026-47075)
Summary
Vulnerability in hackney (CVE-2026-47075). Data can be tampered with by attackers. Mitigation: upgrade to 4.0.1 or later.
Original description
The description as published by the source.
Summary
Improper Neutralization of CRLF Sequences vulnerability in benoitc hackney allows HTTP Request Splitting. hackney does not percent-encode carriage return (\r) or line feed (\n) 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 0.13.1 before 4.0.1.
Source: OSV.dev (Open Source Vulnerabilities) NVD GitHub Advisory OSV
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-47075 has been found in hackney.
Data can be tampered with by attackers. CVSS score: 7.5/10.
What to do: upgrade hackney to 4.0.1 or later.
If unsure, ask your IT team or search "hackney CVE-2026-47075" on the vendor's site.
CVE-2026-47075 (hackney) — CWE-93 / CVSS v3 7.5
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Patched: 4.0.1 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (CWE-93) exists in hackney.
Check the vendor advisory for the affected versions of hackney.
Severity: High (CVSS 7.5/10). Data can be tampered with by attackers.
Update to 4.0.1.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'hackney' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
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1Identify exposure identify
grep -r 'hackney' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
hackneyを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade hackney to 4.0.1ステージング環境で 4.0.1 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
-
3Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
References
- advisory github.com
- advisory nvd.nist.gov
- package hex.pm
- package github.com
- patch github.com
- web cna.erlef.org
- web osv.dev
- web github.com