CVE-2019-10255
MEDIUMCVE-2019-10255 is a medium-severity (CVSS 6.1) Open Redirect vulnerability in notebook. O3 Security confirms whether CVE-2019-10255 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Open Redirect vulnerability in jupyterhub and notebook
Blast Radius
notebook🐍jupyterhubReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
Description
An Open Redirect vulnerability for all browsers in Jupyter Notebook before 5.7.7 and some browsers (Chrome, Firefox) in JupyterHub before 0.9.5 allows crafted links to the login page, which will redirect to a malicious site after successful login. Servers running on a base_url prefix are not affected.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | notebook | all versions | 5.7.8 |
| 🐍PyPI | jupyterhub | all versions | 0.9.6 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for notebook. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update notebook to 5.7.8 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2019-10255 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2019-10255 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2019-10255. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2019-10255 in your dependencies?
O3 detects CVE-2019-10255 across PyPI dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.