Vulnerability in mermaid (CVE-2026-41150)
Summary
Vulnerability in mermaid (CVE-2026-41150). Risk of unauthorized operations or information disclosure. Exploitable via excludes. Mitigation: upgrade to 10.9.6 or later.
Original description
The description as published by the source.
Mermaid is a JavaScript tool that uses Markdown-inspired text to create and modify diagrams and charts. Prior to 10.9.6 and 11.15.0, there is a denial-of-service attack when rendering gantt charts, if they use the excludes attribute to exclude all dates. mermaid.parse is unaffected, unless you then call the ganttDb.getTasks() (which is called when rendering a diagram). This vulnerability is fixed in 10.9.6 and 11.15.0.
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-2026-41150 has been found in mermaid.
Attackers can target a specific entry point like excludes over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: 5.3/10.
What to do: upgrade mermaid to 10.9.6 or later.
If unsure, ask your IT team or search "mermaid CVE-2026-41150" on the vendor's site.
CVE-2026-41150 (mermaid) — CWE-835 / CVSS v3 5.3
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: excludes / mermaid.parse
Patched: 10.9.6 — apply immediately
Workaround: There are no workarounds available without updating to a newer version of mermaid.
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-835) exists in mermaid. Attackers reach the vulnerable code path via excludes without authentication.
Check the vendor advisory for the affected versions of mermaid. Attack surface: excludes / mermaid.parse.
Severity: Medium (CVSS 5.3/10). Risk of unauthorized operations or information disclosure.
Update to 10.9.6.
Workaround: There are no workarounds available without updating to a newer version of mermaid.
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
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。 -
2Apply temporary workaround mitigate
There are no workarounds available without updating to a newer version of mermaid.パッチが適用されるまでの応急処置として、There are no workarounds available without updating to a newer version of mermaid. 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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3Apply patch patch
Upgrade mermaid to 10.9.6ステージング環境で 10.9.6 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。
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4Post-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
Fix status by distribution
Fixed packages published by each distribution for this CVE
- Debian DEBIAN-CVE-2026-41150 node-mermaid
- Ubuntu UBUNTU-CVE-2026-41150 node-mermaid
References
- advisory github.com
- advisory nvd.nist.gov
- advisory github.com
- package github.com
- patch github.com
- patch github.com
- web github.com
- web github.com
- web github.com