# CVE-2019-10255: Open Redirect vulnerability in jupyterhub and notebook

> Crafted links to the login page redirect users to malicious sites after successful login, affecting Jupyter Notebook and Hub installations without a base_url prefix.

- **Severity:** Medium 6.1 (`CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 28 Mar 2019
- **Updated:** 4 Aug 2024
- **Also known as:** DEBIAN-CVE-2019-10255, GHSA-rv62-4pmj-xw6h, PYSEC-2026-2683, PYSEC-2026-647, UBUNTU-CVE-2019-10255

## What is CVE-2019-10255?

CVE-2019-10255 is a medium-severity vulnerability in n/a, published on 28 Mar 2019. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official 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.

Weakness: CWE-601 (URL Redirection to Untrusted Site)

## Which versions are affected by CVE-2019-10255?

6 open source packages ship an affected version, including jupyterhub and notebook. It affects 2 products.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `jupyterhub` | PyPI | All versions | 0.9.6 |
| `jupyterhub` | PyPI | All versions | 0.9.6 |
| `jupyterhub` | PyPI | All versions | 0.9.6 |
| `notebook` | PyPI | All versions | 5.7.8 |
| `notebook` | PyPI | All versions | 5.7.8 |
| `notebook` | PyPI | All versions | 5.7.8 |

Products: Jupyter Jupyterhub, Jupyter Notebook.

## How do I fix CVE-2019-10255?

Upgrade jupyterhub to 0.9.6 or later.

## Is CVE-2019-10255 being exploited?

There is no known exploitation of CVE-2019-10255 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2024-28233](https://insights.sbomify.com/CVE-2024-28233/): XSS in JupyterHub via Self-XSS leveraged by Cookie Tossing (high 8.1)
- [CVE-2024-41942](https://insights.sbomify.com/CVE-2024-41942/): JupyterHub has a privilege escalation vulnerability with the `admin:users` scope (high 7.2)
- [CVE-2026-40864](https://insights.sbomify.com/CVE-2026-40864/): JupyterHub: Cross-origin form POSTs bypass XSRF (medium 5.4)
- [CVE-2026-33709](https://insights.sbomify.com/CVE-2026-33709/): JupyterHub has an Open Redirect Vulnerability (medium 5.1)
- [CVE-2020-36191](https://insights.sbomify.com/CVE-2020-36191/): Cross-Site Request Forgery in JupyterHub (medium 4.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2019-10255 and fix it if it is affected.

What it is: CVE-2019-10255 is a medium-severity vulnerability in n/a, published on 28 Mar 2019. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2019-10255 in the wild and no public exploit code.

Affected packages and fixed versions:
- jupyterhub (PyPI): affected all versions; fixed in 0.9.6
- jupyterhub (PyPI): affected all versions; fixed in 0.9.6
- jupyterhub (PyPI): affected all versions; fixed in 0.9.6
- notebook (PyPI): affected all versions; fixed in 5.7.8
- notebook (PyPI): affected all versions; fixed in 5.7.8
- notebook (PyPI): affected all versions; fixed in 5.7.8

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2019-10255/ (Markdown: https://insights.sbomify.com/CVE-2019-10255/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2019-10255
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2019-10255
- OSV: https://osv.dev/vulnerability/CVE-2019-10255

---
From sbomify Insights: https://insights.sbomify.com/CVE-2019-10255/
Summaries are generated and may contain mistakes; the official description above is the record.