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CVE-2026-35397
high
CVSS 8.8
Path Traversal in jupyter-server (CVE-2026-35397)
Summary
path traversal in jupyter-server (CVE-2026-35397). Confidential information can be exposed externally. Exploitable via ``root_dir``. Mitigation: upgrade to `2.18.0` or later.
AI summary snake-internal / snake-material-v2
A vulnerability tracked as **CVE-2026-35397** has been found in jupyter-server.
Attackers can target a specific entry point like ``root_dir`` over the network to misuse the product.
Confidential information can be exposed externally. CVSS score: 8.8/10.
What to do: upgrade jupyter-server to **2.18.0** or later.
If unsure, ask your IT team or search "jupyter-server CVE-2026-35397" on the vendor's site.
CVE-2026-35397 (jupyter-server) — CWE-22 / CVSS v3 8.8
Attack vector: remote (network-reachable) / no user interaction
Attack surface: `root_dir` / `user1` / `user2` / `user3`
Patched: `2.18.0` — apply immediately
Workaround: Use folder names that do not overlap.
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
**Path traversal** (CWE-22) exists in jupyter-server. Attackers reach the vulnerable code path via ``root_dir`` without authentication.
📍 Affected scope
jupyter-server — . Attack surface: `root_dir` / `user1` / `user2` / `user3`.
🔥 Severity
Severity: High (CVSS 8.8/10). Confidential information can be exposed externally
🔧 How to fix
Update to **2.18.0**.
🛡️ Workaround
Workaround: Use folder names that do not overlap.
🔍 Detection
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run `grep -r 'jupyter-server' .` 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 'jupyter-server' . | 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 `jupyter-server` 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
Use folder names that do not overlap.パッチが適用されるまでの応急処置として、Use folder names that do not overlap. 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 jupyter-server to 2.18.0ステージング環境で 2.18.0 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
pip
jupyter-server
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.18.0"}]}]
PyPI
jupyter-server
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.18.0"}]}]