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CVE-2026-71438
Vulnerability in mermaid (CVE-2026-71438)
Summary
vulnerability in mermaid (CVE-2026-71438). Risk of unauthorized operations or information disclosure. Exploitable via ``mermaid.initialize``. Mitigation: upgrade to `10.9.8` or later.
AI summary snake-internal / snake-material-v2
A vulnerability tracked as **CVE-2026-71438** has been found in mermaid.
Attackers can target a specific entry point like ``mermaid.initialize`` over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: ?/10.
What to do: upgrade mermaid to **10.9.8** or later.
If unsure, ask your IT team or search "mermaid CVE-2026-71438" on the vendor's site.
CVE-2026-71438 (mermaid) — CWE-1321 /
Attack surface: `mermaid.initialize` / `mermaidAPI.setConfig` / `mermaidAPI.updateSiteConfig` / `assignWithDepth`
Patched: `10.9.8` — apply immediately
Workaround: Don't pass user-controlled data to the `mermaid.initialize`, `mermaidAPI.setConfig`, and `mermaidAPI.updateSiteConfig` functions.
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-1321) exists in mermaid. Attackers reach the vulnerable code path via ``mermaid.initialize`` without authentication.
📍 Affected scope
mermaid — . Attack surface: `mermaid.initialize` / `mermaidAPI.setConfig` / `mermaidAPI.updateSiteConfig` / `assignWithDepth`.
🔥 Severity
Severity: ?. Risk of unauthorized operations or information disclosure
🔧 How to fix
Update to **10.9.8**.
🛡️ Workaround
Workaround: Don't pass user-controlled data to the `mermaid.initialize`, `mermaidAPI.setConfig`, and `mermaidAPI.updateSiteConfig` functions.
🔍 Detection
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run `grep -r 'mermaid' .` 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 'mermaid' . | 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 `mermaid` 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
Don't pass user-controlled data to the `mermaid.initialize`, `mermaidAPI.setConfig`, and `mermaidAPI.updateSiteConfig` functions.パッチが適用されるまでの応急処置として、Don't pass user-controlled data to the `mermaid.initialize`, `mermaidAPI.setConfig`, and `mermaidAPI.updateSiteConfig` functions. 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 mermaid to 10.9.8ステージング環境で 10.9.8 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
mermaid
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"10.9.8"}]}]