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CVE-2026-44665
XXE (XML External Entity) in fast-xml-builder (CVE-2026-44665)
Summary
vulnerability in fast-xml-builder (CVE-2026-44665). Risk of unauthorized operations or information disclosure. Mitigation: upgrade to `1.1.7` or later.
AI summary snake-internal / snake-material-v2
A vulnerability tracked as **CVE-2026-44665** has been found in fast-xml-builder.
Risk of unauthorized operations or information disclosure. CVSS score: ?/10.
What to do: upgrade fast-xml-builder to **1.1.7** or later.
If unsure, ask your IT team or search "fast-xml-builder CVE-2026-44665" on the vendor's site.
CVE-2026-44665 (fast-xml-builder) — CWE-611 /
Patched: `1.1.7` — apply immediately
Workaround: If you're not ignoring attributes then keep processEntities flag true.
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-611) exists in fast-xml-builder.
📍 Affected scope
fast-xml-builder — .
🔥 Severity
Severity: ?. Risk of unauthorized operations or information disclosure
🔧 How to fix
Update to **1.1.7**.
🛡️ Workaround
Workaround: If you're not ignoring attributes then keep processEntities flag true.
🔍 Detection
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run `grep -r 'fast-xml-builder' .` 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 'fast-xml-builder' . | 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 `fast-xml-builder` 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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5Apply temporary workaround mitigate
If you're not ignoring attributes then keep processEntities flag true.パッチが適用されるまでの応急処置として、If you're not ignoring attributes then keep processEntities flag true. を実施。回避策の副作用 (機能低下) を確認した上で。
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6Apply patch patch
Upgrade fast-xml-builder to 1.1.7ステージング環境で 1.1.7 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
npm
fast-xml-builder
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.1.7"}]}]