The Jupyter Server provides the backend (i.e. the core services, APIs, and REST endpoints) for Jupyter web applications like Jupyter notebook, JupyterLab, and Voila. In Jupyter Server before version 1
The Jupyter Server provides the backend (i.e. the core services, APIs, and REST endpoints) for Jupyter web applications like Jupyter notebook, JupyterLab, and Voila. In Jupyter Server before version 1.1.1, an open redirect vulnerability could cause the jupyter server to redirect the browser to a different malicious website. All jupyter servers running without a base_url prefix are technically affected, however, these maliciously crafted links can only be reasonably made for known jupyter server hosts. A link to your jupyter server may appear safe, but ultimately redirect to a spoofed server on the public internet. This same vulnerability was patched in upstream notebook v5.7.8. This is fixed in jupyter_server 1.1.1. If upgrade is not available, a workaround can be to run your server on a url prefix: "jupyter server --ServerApp.base_url=/jupyter/".
Affected software
Click a technology to see all vulnerabilities affecting it.
| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| Python (PyPI) | jupyter-server | < 1.1.1 | 1.1.1 |
References
- https://github.com/jupyter-server/jupyter_server/commit/85e4abccf6ea9321d29153f73b0bd72ccb3a6bca
- https://github.com/jupyter-server/jupyter_server/security/advisories/GHSA-9f66-54xg-pc2c
- https://pypi.org/project/jupyter-server/
- https://advisory.checkmarx.net/advisory/CX-2020-4291
- https://nvd.nist.gov/vuln/detail/CVE-2020-26275
- https://github.com/jupyter-server/jupyter_server
- https://github.com/pypa/advisory-database/tree/main/vulns/jupyter-server/PYSEC-2020-346.yaml
- https://github.com/pypa/advisory-database/tree/main/vulns/jupyter-server/PYSEC-2020-50.yaml
- https://pypi.org/project/jupyter-server
- CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N- Weakness (CWE)
CWE-601- Platform
- Python (PyPI)
- Package
jupyter-server- Disclosed
- 21.12.2020
- Updated
- 11.10.2026 13:19
Sources and licenses
OSV / GitHub Advisory Database - PYSEC-2020-346 - PyPA Advisory Database; CC BY 4.0
OSV / GitHub Advisory Database - GHSA-9f66-54xg-pc2c - CC BY 4.0
OSV / GitHub Advisory Database - PYSEC-2020-50 - PyPA Advisory Database; CC BY 4.0
Vulnerability history: jupyter-server
All published vulnerabilities of this package (Python (PyPI)), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 14
- First → latest
- 11.2020 09.2026
- Without a fix
- 0
- Exploited in attacks
- 0
Severity breakdown
- Critical 1
- High 7
- Medium 6
Disclosures per year
- 2020: 2
- 2021: 0
- 2022: 2
- 2023: 3
- 2024: 1
- 2025: 0
- 2026: 6
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The Jupyter Server provides the backend (i.e. the core services, APIs, and REST endpoints) for Jupyter web applications like Jupyter notebook, JupyterLab, and Voila. In Jupyter Server before version 1 this entry
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