{"id":"UBUNTU-CVE-2026-54338","details":"JupyterHub is software that allows users to create a multi-user server for Jupyter notebooks. Prior to 5.5.0, invalid input to form-based login authenticators can place an unbounded attacker-controlled username in failed-login logs, allowing an unauthenticated attacker to consume logging and storage resources. This issue is fixed in version 5.5.0.","modified":"2026-08-13T00:10:32Z","published":"2026-08-07T21:17:00Z","upstream":["CVE-2026-54338"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-54338"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-54338"},{"type":"REPORT","url":"https://github.com/jupyterhub/jupyterhub/commit/d6dc595f84b7509969686da31d87d6d69e7fce0a"},{"type":"REPORT","url":"https://github.com/jupyterhub/jupyterhub/security/advisories/GHSA-p43p-whwx-q52h"}],"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-2026-54338.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_name":"jupyterhub","binary_version":"3.0.0+ds1-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-54338.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_version":"5.2.1+ds1-4","binary_name":"jupyterhub"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-54338.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L"},{"type":"Ubuntu","score":"medium"}]}