CVE-2026-108752

low

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.

References

https://www.vulncheck.com/advisories/jupyterhub-through-6.0.1-oauth-client-id-collision-via-unescaped-hyphen

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/user.py#L1174-L1186

https://github.com/jupyterhub/jupyterhub/blob/3e516c6f382b481e815ec455befb2f14d80d337b/jupyterhub/oauth/provider.py#L719-L754

https://github.com/jupyterhub/jupyterhub

https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-96917

Details

Source: Mitre, NVD

Published: 2026-10-11

Updated: 2026-10-11

Risk Information

CVSS v2

Base Score: 3.6

Vector: CVSS2#AV:N/AC:H/Au:S/C:N/I:P/A:P

Severity: Low

CVSS v3

Base Score: 4.2

Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:L

Severity: Medium

CVSS v4

Base Score: 2.3

Vector: 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

Severity: Low