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CVE-2026-54570
medium
CVSS 6.9
Vulnerability in AngleSharp (CVE-2026-54570)
Summary
vulnerability in AngleSharp (CVE-2026-54570). Data can be tampered with by attackers. Exploitable via ``MathAnnotationXmlElement``. Mitigation: upgrade to `1.5.0` or later.
AI summary snake-internal / snake-material-v2
A vulnerability tracked as **CVE-2026-54570** has been found in AngleSharp.
Attackers can target a specific entry point like ``MathAnnotationXmlElement`` over the network to misuse the product.
Data can be tampered with by attackers. CVSS score: 6.9/10.
What to do: upgrade AngleSharp to **1.5.0** or later.
If unsure, ask your IT team or search "AngleSharp CVE-2026-54570" on the vendor's site.
CVE-2026-54570 (AngleSharp) — CWE-80 / CVSS v3 6.9
Attack vector: remote (network-reachable) / unauthenticated
Attack surface: `MathAnnotationXmlElement` / `HtmlTip` / `AllForeignExceptions` / `innerHTML`
Patched: `1.5.0` — 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-80) exists in AngleSharp. Attackers reach the vulnerable code path via ``MathAnnotationXmlElement`` without authentication.
📍 Affected scope
AngleSharp — . Attack surface: `MathAnnotationXmlElement` / `HtmlTip` / `AllForeignExceptions` / `innerHTML`.
🔥 Severity
Severity: Medium (CVSS 6.9/10). Data can be tampered with by attackers
🔧 How to fix
Update to **1.5.0**.
🛡️ 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 'AngleSharp' .` 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 'AngleSharp' . | 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 `AngleSharp` 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 AngleSharp to 1.5.0ステージング環境で 1.5.0 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
nuget
AngleSharp
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.5.0"}]}]