← Back
CVE-2026-42266
high
CVSS 8.8
Vulnerability in jupyterlab (CVE-2026-42266)
Summary
vulnerability in jupyterlab (CVE-2026-42266). Successful exploitation can lead to full system takeover. Exploitable via ``allowed_extensions_uris``. Mitigation: upgrade to `4.5.7` or later.
AI summary snake-internal / snake-material-v2
A vulnerability tracked as **CVE-2026-42266** has been found in jupyterlab.
Attackers can target a specific entry point like ``allowed_extensions_uris`` over the network to misuse the product.
Successful exploitation can lead to full system takeover. CVSS score: 8.8/10.
What to do: upgrade jupyterlab to **4.5.7** or later.
If unsure, ask your IT team or search "jupyterlab CVE-2026-42266" on the vendor's site.
CVE-2026-42266 (jupyterlab) — CWE-88 / CVSS v3 8.8
Attack vector: remote (network-reachable) / no user interaction
Attack surface: `allowed_extensions_uris` / `jupyterlab`
Patched: `4.5.7` — 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-88) exists in jupyterlab. Attackers reach the vulnerable code path via ``allowed_extensions_uris`` without authentication.
📍 Affected scope
jupyterlab — . Attack surface: `allowed_extensions_uris` / `jupyterlab`.
🔥 Severity
Severity: High (CVSS 8.8/10). Successful exploitation can lead to full system takeover
🔧 How to fix
Update to **4.5.7**.
🛡️ 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 'jupyterlab' .` 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
-
1Identify exposure identify
grep -r 'jupyterlab' . | 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 `jupyterlab` を grep し、稼働しているサービス・バージョンを把握する。
-
6Apply patch patch
Upgrade jupyterlab to 4.5.7ステージング環境で 4.5.7 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。
-
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
Bitnami
jupyterlab
[{"type":"SEMVER","events":[{"introduced":"4.0.0"},{"fixed":"4.5.7"}]}]
PyPI
jupyterlab
[{"type":"ECOSYSTEM","events":[{"introduced":"4.0.0"},{"fixed":"4.5.7"}]}]
pip
jupyterlab
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.5.7"}]}]
References
- advisory https://nvd.nist.gov/vuln/detail/CVE-2026-42266
- package https://github.com/jupyterlab/jupyterlab
- patch [email protected]
- patch [email protected]
- web [email protected]
- web [email protected]
- web https://github.com/advisories/GHSA-37w4-hwhx-4rc4
- web https://github.com/pypa/advisory-database/tree/main/vulns/jupyterlab/PYSEC-2026-164.yaml
- web 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- web 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- web 0b0ca135-0b70-47e7-9f44-1890c2a1c46c