Vulnerability in Gazelle (CVE-2026-40562)
Summary
Vulnerability in Gazelle (CVE-2026-40562). Data can be tampered with by attackers.
Original description
The description as published by the source.
Gazelle versions through 0.49 for Perl allows HTTP Request Smuggling via Improper Header Precedence.
Gazelle incorrectly prioritizes "Content-Length" over "Transfer-Encoding: chunked" when both headers are present in an HTTP request. Per RFC 7230 3.3.3, Transfer-Encoding must take precedence.
An attacker could exploit this to smuggle malicious HTTP requests via a front-end reverse proxy.
Source: NIST National Vulnerability Database NVD
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-2026-40562 has been found in Gazelle.
Data can be tampered with by attackers. CVSS score: 7.5/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Gazelle CVE-2026-40562" on the vendor's site.
CVE-2026-40562 (Gazelle) — CWE-444 / CVSS v3 7.5
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
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-444) exists in Gazelle.
Check the vendor advisory for the affected versions of Gazelle.
Severity: High (CVSS 7.5/10). Data can be tampered with by attackers.
Update to the patched release per vendor advisory.
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 'Gazelle' . 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 'Gazelle' . | 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
Gazelleを grep し、稼働しているサービス・バージョンを把握する。 -
2Post-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。
References
- advisory metacpan.org
- advisory github.com
- advisory nvd.nist.gov
- package github.com
- patch security.metacpan.org
- web datatracker.ietf.org
- web openwall.com
- web cpan.org