Vulnerability in hackney (CVE-2026-47077)
Summary
Vulnerability in hackney (CVE-2026-47077). Risk of unauthorized operations or information disclosure. Exploitable via stream_data. Mitigation: upgrade to 4.0.1 or later.
Original description
The description as published by the source.
Summary
Allocation of Resources Without Limits or Throttling vulnerability in benoitc hackney allows Flooding. hackney_h3:await_response_loop/6 accumulates the HTTP/3 response body in memory without any size cap. The after Timeout clause is a per-message inactivity timer that resets on every received chunk, housekeeping message, or settings frame — it is not a wall-clock deadline. A malicious HTTP/3 server that emits one small chunk every Timeout - 1 ms with Fin = false and never sends a final frame keeps the loop alive indefinitely while the accumulation buffer grows linearly without bound, eventually exhausting the BEAM process heap and causing an out-of-memory condition.
This issue affects hackney: from 2.0.0 before 4.0.1.
Configurations
The application must use the HTTP/3 transport by calling hackney_h3 directly or by passing {transport, h3} to hackney:request/5. The default hackney transport (TCP/TLS) is not affected.
Source: GitHub Security Advisories (Global) NVD GitHub Advisory
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-2026-47077 has been found in hackney.
Attackers can target a specific entry point like stream_data over the network to misuse the product.
Risk of unauthorized operations or information disclosure. 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-2026-47077" on the vendor's site.
CVE-2026-47077 (hackney) — CWE-295 / CVSS v3 7.5
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: stream_data / select / settings / max_body
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-295) exists in hackney. Attackers reach the vulnerable code path via stream_data without authentication.
Check the vendor advisory for the affected versions of hackney. Attack surface: stream_data / select / settings / max_body.
Severity: High (CVSS 7.5/10). Risk of unauthorized operations or information disclosure.
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
-
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
- web github.com
- web github.com