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CVE-2026-41511
medium
CVSS 6.2
Vulnerability in OpenMcdf (CVE-2026-41511)
Summary
vulnerability in OpenMcdf (CVE-2026-41511). Risk of unauthorized operations or information disclosure. Exploitable via ``LeftSiblingID``. Mitigation: upgrade to `3.1.3` or later.
AI summary snake-internal / snake-material-v2
A vulnerability tracked as **CVE-2026-41511** has been found in OpenMcdf.
Attackers can target a specific entry point like ``LeftSiblingID`` over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: 6.2/10.
What to do: upgrade OpenMcdf to **3.1.3** or later.
If unsure, ask your IT team or search "OpenMcdf CVE-2026-41511" on the vendor's site.
CVE-2026-41511 (OpenMcdf) — CWE-835 / CVSS v3 6.2
Attack vector: local / unauthenticated / no user interaction
Attack surface: `LeftSiblingID` / `RightSiblingID` / `DirectoryTreeEnumerator` / `DirectoryTree.TryGetDirectoryEntry`
Patched: `3.1.3` — 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-835) exists in OpenMcdf. Attackers reach the vulnerable code path via ``LeftSiblingID`` without authentication.
📍 Affected scope
OpenMcdf — . Attack surface: `LeftSiblingID` / `RightSiblingID` / `DirectoryTreeEnumerator` / `DirectoryTree.TryGetDirectoryEntry`.
🔥 Severity
Severity: Medium (CVSS 6.2/10). Risk of unauthorized operations or information disclosure
🔧 How to fix
Update to **3.1.3**.
🛡️ 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 'OpenMcdf' .` 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 'OpenMcdf' . | 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 `OpenMcdf` 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 OpenMcdf to 3.1.3ステージング環境で 3.1.3 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
OpenMcdf
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.1.3"}]}]