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CVE-2026-47220
high
CVSS 7.5
Vulnerability in envoy (CVE-2026-47220)
Summary
vulnerability in envoy (CVE-2026-47220). Risk of unauthorized operations or information disclosure. Exploitable via `Host header`. Mitigation: upgrade to `1.37.5` or later.
AI summary snake-internal / snake-material-v2
A vulnerability tracked as **CVE-2026-47220** has been found in envoy.
Attackers can target a specific entry point like `Host header` over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: 7.5/10.
What to do: upgrade envoy to **1.37.5** or later.
If unsure, ask your IT team or search "envoy CVE-2026-47220" on the vendor's site.
CVE-2026-47220 (envoy) — CWE-476 / CVSS v3 7.5
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: Host header
Patched: `1.37.5` — 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.
❓ What is the problem
**A vulnerability** (CWE-476) exists in envoy. Attackers reach the vulnerable code path via `Host header` without authentication.
📍 Affected scope
envoy — . Attack surface: Host header.
🔥 Severity
Severity: High (CVSS 7.5/10). Risk of unauthorized operations or information disclosure
🔧 How to fix
Update to **1.37.5**.
🛡️ Workaround
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
🔍 Detection
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run `grep -r 'envoy' .` against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response Actions (7 steps)
Concrete steps and command examples for SOC/SRE teams to execute in order
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1Identify exposure identify
grep -r 'envoy' . | 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 `envoy` を grep し、稼働しているサービス・バージョンを把握する。
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6Apply patch patch
Upgrade envoy to 1.37.5ステージング環境で 1.37.5 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と、Step 3 で見つけた異常検知の続報チェックを含めること。
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7Post-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 Step 3 と同じログクエリでアラート再発が無いか継続監視。
Affected packages
Bitnami
envoy
[{"type":"SEMVER","events":[{"introduced":"1.37.0"},{"fixed":"1.37.5"},{"introduced":"1.38.0"},{"fixed":"1.38.3"}]}]
References
- web https://github.com/envoyproxy/envoy/security/advisories/GHSA-j9wh-4qfm-wf2v
- web https://access.redhat.com/security/cve/CVE-2026-47220
- web https://bugzilla.redhat.com/show_bug.cgi?id=2493652
- web https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-47220.json
- web https://nvd.nist.gov/vuln/detail/CVE-2026-47220