{"id":"UBUNTU-CVE-2026-108752","details":"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.","modified":"2026-10-14T03:22:50.890602700Z","published":"2026-10-13T00:00:00Z","upstream":["CVE-2026-108752"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-108752"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-108752"},{"type":"REPORT","url":"https://github.com/jupyterhub/jupyterhub"},{"type":"REPORT","url":"https://github.com/jupyterhub/jupyterhub/blob/3e516c6f382b481e815ec455befb2f14d80d337b/jupyterhub/oauth/provider.py#L719-L754"},{"type":"REPORT","url":"https://github.com/jupyterhub/jupyterhub/blob/3e516c6f382b481e815ec455befb2f14d80d337b/jupyterhub/user.py#L1174-L1186"},{"type":"REPORT","url":"https://github.com/jupyterhub/jupyterhub/blob/3e516c6f382b481e815ec455befb2f14d80d337b/jupyterhub/user.py#L563-L567"},{"type":"REPORT","url":"https://hackmd.io/@haind/jupyterhub-oauth-client-id-cross-user-collision"},{"type":"REPORT","url":"https://www.vulncheck.com/advisories/jupyterhub-through-6.0.1-oauth-client-id-collision-via-unescaped-hyphen"}],"affected":[{"package":{"name":"jupyterhub","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/jupyterhub?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.0.0+ds1-1","2.0.0+ds1-2"],"ecosystem_specific":{"binaries":[{"binary_name":"jupyterhub","binary_version":"2.0.0+ds1-2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-108752.json"}},{"package":{"name":"jupyterhub","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/jupyterhub?arch=source&distro=noble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.0.0+ds1-1"],"ecosystem_specific":{"binaries":[{"binary_version":"3.0.0+ds1-1","binary_name":"jupyterhub"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-108752.json"}},{"package":{"name":"jupyterhub","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/jupyterhub?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["5.2.1+ds1-4"],"ecosystem_specific":{"binaries":[{"binary_name":"jupyterhub","binary_version":"5.2.1+ds1-4"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-108752.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:L"},{"type":"CVSS_V4","score":"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"},{"type":"Ubuntu","score":"medium"}]}