---
id: CVE-2024-28233
aliases:
  - GHSA-7r3h-4ph8-w38g
  - BIT-jupyterhub-2024-28233
  - PYSEC-2026-1480
title: >-
  Cross site scripting (XSS) in JupyterHub via Self-XSS leveraged by Cookie
  Tossing
summary: >-
  Cross site scripting (XSS) in JupyterHub via Self-XSS leveraged by Cookie
  Tossing
severity: high
cvss: 8.1
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N'
vendor: jupyterhub
product: jupyterhub
ecosystem: pip
affected:
  - jupyterhub < 4.1.0
patched:
  - jupyterhub 4.1.0
published: '2024-03-28'
updated: '2026-09-10'
sourceUpdated: '2026-09-10T03:50:00.245591053Z'
source: OSV
sourceUrl: 'https://osv.dev/vulnerability/GHSA-7r3h-4ph8-w38g'
references:
  - url: >-
      https://github.com/jupyterhub/jupyterhub/security/advisories/GHSA-7r3h-4ph8-w38g
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2024-28233'
  - url: >-
      https://github.com/jupyterhub/jupyterhub/commit/e2798a088f5ad45340fe79cdf1386198e664f77f
  - url: 'https://github.com/jupyterhub/jupyterhub'
tags:
  - osv
  - pip
epss: 0.00329
epssPercentile: 0.26247
ingestedAt: '2026-07-08T18:25:47.204Z'
---

## Overview

### Impact

Affected configurations:

- Single-origin JupyterHub deployments
- JupyterHub deployments with user-controlled applications running on subdomains or peer subdomains of either the Hub or a single-user server.

By tricking a user into visiting a malicious subdomain, the attacker can achieve an XSS directly affecting the former's session. More precisely, in the context of JupyterHub, this XSS could achieve the following:

- Full access to JupyterHub API and user's single-user server, e.g.
  - Create and exfiltrate an API Token
  - Exfiltrate all files hosted on the user's single-user server: notebooks, images, etc.
  - Install malicious extensions. They can be used as a backdoor to silently regain access to victim's session anytime.

### Patches

To prevent cookie-tossing:

- Upgrade to JupyterHub 4.1 (both hub and user environment)
- enable per-user domains via `c.JupyterHub.subdomain_host = "https://mydomain.example.org"`
- set `c.JupyterHub.cookie_host_prefix_enabled = True` to enable domain-locked cookies

or, if available (applies to earlier JupyterHub versions):

- deploy jupyterhub on its own domain, not shared with any other services
- enable per-user domains via `c.JupyterHub.subdomain_host = "https://mydomain.example.org"`

## Affected packages

- `jupyterhub < 4.1.0`

## Remediation

Upgrade to a patched release:

- `jupyterhub 4.1.0`