CVE-2026-108752
JupyterHub through 6.0.1 OAuth Client ID Collision via Unescaped Hyphen
- State
- Published
- Severity
- 2.3 Low
- Published
- Oct 11, 2026
- Updated
- Oct 13, 2026
- Reserved
- Oct 11, 2026
Description
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 2.3 Low | CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N | VulnCheck |
| 3.1 | 4.2 Medium | CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:L | VulnCheck |
Weaknesses
- CWE-694 Use of Multiple Resources with Duplicate Identifier
Affected Products
| Product | Versions |
|---|---|
jupyterhubjupyterhub |
|
References
- https://hackmd.io/@haind/jupyterhub-oauth-client-id-cross-user-collisionthird-party-advisory
- https://github.com/jupyterhub/jupyterhub/blob/3e516c6f382b481e815ec455befb2f14d80d337b/jupyterhub/user.py#L563-L567technical-description
- https://github.com/jupyterhub/jupyterhub/blob/3e516c6f382b481e815ec455befb2f14d80d337b/jupyterhub/oauth/provider.py#L719-L754technical-description
- https://github.com/jupyterhub/jupyterhub/blob/3e516c6f382b481e815ec455befb2f14d80d337b/jupyterhub/user.py#L1174-L1186technical-description
- https://github.com/jupyterhub/jupyterhubproduct
- VulnCheck Advisory: JupyterHub through 6.0.1 OAuth Client ID Collision via Unescaped Hyphenthird-party-advisory
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