CVE-2019-9644 — jupyter-notebook
MEDIUMCVE-2019-9644 is a medium-severity (CVSS 5.4) Cross-site Scripting (XSS) vulnerability in jupyter-notebook. A fix is available for jupyter-notebook — see the affected versions and patch details below.
Improper Neutralization of Input During Web Page Generation in Jupyter Notebook
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2019-9644 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,636 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
jupyter-notebook🐍notebookReal-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 XSSI (cross-site inclusion) vulnerability in Jupyter Notebook before 5.7.6 allows inclusion of resources on malicious pages when visited by users who are authenticated with a Jupyter server. Access to the content of resources has been demonstrated with Internet Explorer through capturing of error messages, though not reproduced with other browsers. This occurs because Internet Explorer's error messages can include the content of any invalid JavaScript that was encountered.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | jupyter-notebook | all versions | 5.7.6pip install --upgrade 'jupyter-notebook==5.7.6' |
| 🐍PyPI | notebook | all versions | 5.7.6pip install --upgrade 'notebook==5.7.6' |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for jupyter-notebook, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update jupyter-notebook to 5.7.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2019-9644 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 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2019-9644 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2019-9644. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
Frequently Asked Questions
Is CVE-2019-9644 in your dependencies?
O3 Security finds CVE-2019-9644 across PyPI dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.