Sign in Sign up
JA · EN · FR
SecPulse
Categories
CVE-2026-54338 medium CVSS 5.3

Vulnerability in jupyterhub (CVE-2026-54338)

Summary

Vulnerability in jupyterhub (CVE-2026-54338). Risk of unauthorized operations or information disclosure. Mitigation: upgrade to 5.5.0 or later.

Original description

The description as published by the source.

JupyterHub is software that allows users to create a multi-user server for Jupyter notebooks. Prior to 5.5.0, invalid input to form-based login authenticators can place an unbounded attacker-controlled username in failed-login logs, allowing an unauthenticated attacker to consume logging and storage resources. This issue is fixed in version 5.5.0.

Source: NIST National Vulnerability Database 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-2026-54338 has been found in jupyterhub.
Risk of unauthorized operations or information disclosure. CVSS score: 5.3/10.
What to do: upgrade jupyterhub to 5.5.0 or later.
If unsure, ask your IT team or search "jupyterhub CVE-2026-54338" on the vendor's site.

CVE-2026-54338 (jupyterhub) — CWE-400 / CVSS v3 5.3
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Patched: 5.5.0 — apply immediately
Workaround: Use an Authenticator that doesn't use a login form, such as OAuthenticator.
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-400) exists in jupyterhub.

📍 Affected scope

Check the vendor advisory for the affected versions of jupyterhub.

🔥 Severity

Severity: Medium (CVSS 5.3/10). Risk of unauthorized operations or information disclosure.

🔧 How to fix

Update to 5.5.0.

🛡️ Workaround

Workaround: Use an Authenticator that doesn't use a login form, such as OAuthenticator.

🔍 Detection

Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'jupyterhub' . 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

  1. 1
    Identify exposure identify 
    grep -r 'jupyterhub' . | 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 jupyterhub を grep し、稼働しているサービス・バージョンを把握する。

  2. 2
    Apply temporary workaround mitigate 
    Use an Authenticator that doesn't use a login form, such as OAuthenticator.

    パッチが適用されるまでの応急処置として、Use an Authenticator that doesn't use a login form, such as OAuthenticator. を実施。回避策の副作用 (機能低下) を確認した上で。

  3. 3
    Apply patch patch 
    Upgrade jupyterhub to 5.5.0

    ステージング環境で 5.5.0 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を含めること。

  4. 4
    Post-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

pip jupyterhub
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.5.0"}]}]
Bitnami jupyterhub
[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"5.5.0"}]}]

Fix status by distribution

Fixed packages published by each distribution for this CVE

References

We use cookies for analytics and ad measurement. This setting applies to all Game co., Ltd. sites. Details