---
id: CVE-2026-108752
title: >-
  JupyterHub through 6.0.1 contains an identifier collision vulnerability that
  allows authenticated users to overwrite another user's named-server OAuth
  client by registering a hyphenated username
summary: >-
  JupyterHub through 6.0.1 contains an identifier collision vulnerability that
  allows authenticated users to overwrite another user's named-server OAuth
  client by registering a hyphenated username. Attackers holding a name like
  alice-prod …
severity: medium
cvss: 4.2
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:L'
cwe:
  - CWE-694
published: '2026-10-11'
updated: '2026-10-11'
sourceUpdated: '2026-10-11T13:17:20.097'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-108752'
references:
  - url: 'https://github.com/jupyterhub/jupyterhub'
    label: disclosure@vulncheck.com
  - url: >-
      https://github.com/jupyterhub/jupyterhub/blob/3e516c6f382b481e815ec455befb2f14d80d337b/jupyterhub/oauth/provider.py#L719-L754
    label: disclosure@vulncheck.com
  - url: >-
      https://github.com/jupyterhub/jupyterhub/blob/3e516c6f382b481e815ec455befb2f14d80d337b/jupyterhub/user.py#L1174-L1186
    label: disclosure@vulncheck.com
  - url: >-
      https://github.com/jupyterhub/jupyterhub/blob/3e516c6f382b481e815ec455befb2f14d80d337b/jupyterhub/user.py#L563-L567
    label: disclosure@vulncheck.com
  - url: 'https://hackmd.io/@haind/jupyterhub-oauth-client-id-cross-user-collision'
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/jupyterhub-through-6.0.1-oauth-client-id-collision-via-unescaped-hyphen
    label: disclosure@vulncheck.com
tags:
  - nvd
ingestedAt: '2026-10-11T13:51:17.038Z'
---

## Overview

JupyterHub through 6.0.1 contains an identifier collision vulnerability that allows authenticated users to overwrite another user's named-server OAuth client by registering a hyphenated username. Attackers holding a name like alice-prod can overwrite the client for alice's server prod, breaking OAuth login and revoking tokens by stopping their own server.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.