Jupyter server Token bruteforcing
Affects: Notebook and Lab between 6.4.0?(potentially earlier) and 6.4.11 (currently latest). Jupyter Server <=1.16.0. If I am correct about the responsible code it will affect Jupyter-Server 1.17.0 and 2.0.0a0 as well.
Description: If notebook server is started with a value of root_dir that contains the starting user's home directory, then the underlying REST API can be used to leak the access token assigned at start time by guessing/brute forcing the PID of the jupyter server. While this requires an authenticated user session, this url can be used from an xss payload (as in CVE-2021-32798) or from a hooked or otherwise compromised browser to leak this access token to a malicious third party. This token can be used along with the REST API to interact with Jupyter services/notebooks such as modifying or overwriting critical files, such as .bashrc or .ssh/authorized_keys, allowing a malicious user to read potentially sensitive data and possibly gain control of the impacted system.
Affected software
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| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| Python (PyPI) | jupyter-server | < 1.17.1, >= 2.0.0a0, < 2.0.0a1 | 1.17.1, 2.0.0a1 |
References
- https://github.com/jupyter-server/jupyter_server/security/advisories/GHSA-q874-g24w-4q9g
- https://nvd.nist.gov/vuln/detail/CVE-2022-29241
- https://github.com/jupyter-server/jupyter_server/commit/3485007abbb459585357212dcaa20521989272e8
- https://github.com/jupyter-server/jupyter_server/commit/877da10cd0d7ae45f8b1e385fa1f5a335e7adf1f
- https://github.com/jupyter-server/jupyter_server
- https://github.com/pypa/advisory-database/tree/main/vulns/jupyter-server/PYSEC-2022-211.yaml
- CVSS vector
CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:H- Weakness (CWE)
-- Platform
- Python (PyPI)
- Package
jupyter-server- Disclosed
- 14.06.2022
- Updated
- 11.10.2026 15:17
Sources and licenses
OSV / GitHub Advisory Database - PYSEC-2022-211 - PyPA Advisory Database; CC BY 4.0
OSV / GitHub Advisory Database - GHSA-q874-g24w-4q9g - 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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