CVE-2026-108752 PUBLISHED

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.

• HaiND from the Post and Telecommunication Institute of Technology finder

• https://hackmd.io/@haind/jupyterhub-oauth-client-id-cross-user-collision
• https://github.com/jupyterhub/jupyterhub/blob/3e516c6f382b481e815ec455befb2f14d80d337b/jupyterhub/user.py#L563-L567
• https://github.com/jupyterhub/jupyterhub/blob/3e516c6f382b481e815ec455befb2f14d80d337b/jupyterhub/oauth/provider.py#L719-L754
• https://github.com/jupyterhub/jupyterhub/blob/3e516c6f382b481e815ec455befb2f14d80d337b/jupyterhub/user.py#L1174-L1186
• https://github.com/jupyterhub/jupyterhub
• VulnCheck Advisory: JupyterHub through 6.0.1 OAuth Client ID Collision via Unescaped Hyphen

• Use of Multiple Resources with Duplicate Identifier CWE