{"id":"CVE-2026-33709","aliases":["BIT-jupyterhub-2026-33709","DEBIAN-CVE-2026-33709","EUVD-2026-18880","GHSA-3vff-hjqv-m7h8","PYSEC-2026-2188","UBUNTU-CVE-2026-33709"],"status":"published","title":"JupyterHub has an Open Redirect Vulnerability","description":"JupyterHub is software that allows one to create a multi-user server for Jupyter notebooks. Prior to version 5.4.4, an open redirect vulnerability in JupyterHub allows attackers to construct links which, when clicked, take users to the JupyterHub login page, after which they are sent to an arbitrary attacker-controlled site outside JupyterHub instead of a JupyterHub page, bypassing JupyterHub's check to prevent this. This issue has been patched in version 5.4.4.","severity":{"version":"4.0","score":5.1,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-09","score":0.00214,"percentile":0.11824,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-601"],"published":"2026-04-03T21:36:07Z","modified":"2026-10-28T02:30:35Z","fixes":[{"ecosystem":"PyPI","package":"jupyterhub","fixed_in":["5.4.4"],"sources":["ghsa","osv"]},{"ecosystem":"Bitnami","package":"jupyterhub","fixed_in":["5.4.4"],"sources":["osv"]}],"affected":[{"source":"ghsa","ecosystem":"PyPI","package":"jupyterhub","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"5.4.3"},{"fixed":"5.4.4"}]}]},{"source":"osv","ecosystem":"Bitnami","package":"jupyterhub","ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"5.4.4"}]}]},{"source":"osv","ecosystem":"Debian:12","package":"jupyterhub","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.0.0+ds1-1","5.0.0+ds1-1","5.0.0+ds1-2","5.0.0+ds1-3","5.0.0+ds1-4","5.2.1+ds1-1","5.2.1+ds1-2","5.2.1+ds1-3","5.2.1+ds1-4","5.2.1+ds1-5"]},{"source":"osv","ecosystem":"Debian:13","package":"jupyterhub","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["5.2.1+ds1-4","5.2.1+ds1-5"]},{"source":"osv","ecosystem":"Debian:14","package":"jupyterhub","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["5.2.1+ds1-4","5.2.1+ds1-5"]},{"source":"osv","ecosystem":"PyPI","package":"jupyterhub","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.4.4"}]}],"versions":["0.1.0","0.2.0","0.3.0","0.4.0","0.4.1","0.5.0","0.6.0","0.6.1","0.7.0","0.7.0b1","0.7.1","0.7.2","0.8.0","0.8.0b1","0.8.0b2","0.8.0b3","0.8.0b4","0.8.0b5","0.8.0rc1","0.8.0rc2","0.8.1","0.9.0","0.9.0b1","0.9.0b2","0.9.0b3","0.9.0rc1","0.9.1","0.9.2","0.9.3","0.9.4","0.9.5","0.9.6","1.0.0","1.0.0b1","1.0.0b2","1.1.0","1.1.0b1","1.2.0","1.2.0b1","1.2.1","1.2.2","1.3.0","1.4.0","1.4.1","1.4.2","1.5.0","1.5.1","2.0.0","2.0.0b1","2.0.0b2","2.0.0b3","2.0.0rc1","2.0.0rc2","2.0.0rc3","2.0.0rc4","2.0.0rc5","2.0.1","2.0.2","2.1.0","2.1.1","2.2.0","2.2.1","2.2.2","2.3.0","2.3.1","3.0.0","3.0.0b1","3.1.0","3.1.1","4.0.0","4.0.0b1","4.0.0b2","4.0.1","4.0.2","4.1.0","4.1.1","4.1.2","4.1.3","4.1.4","4.1.5","4.1.6","5.0.0","5.0.0b1","5.0.0b2","5.1.0","5.2.0","5.2.1","5.3.0","5.3.0rc0","5.4.0","5.4.1","5.4.2","5.4.3"]},{"source":"osv","ecosystem":"PyPI","package":"jupyterhub","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.4.4"}]}],"versions":["0.1.0","0.2.0","0.3.0","0.4.0","0.4.1","0.5.0","0.6.0","0.6.1","0.7.0","0.7.0b1","0.7.1","0.7.2","0.8.0","0.8.0b1","0.8.0b2","0.8.0b3","0.8.0b4","0.8.0b5","0.8.0rc1","0.8.0rc2","0.8.1","0.9.0","0.9.0b1","0.9.0b2","0.9.0b3","0.9.0rc1","0.9.1","0.9.2","0.9.3","0.9.4","0.9.5","0.9.6","1.0.0","1.0.0b1","1.0.0b2","1.1.0","1.1.0b1","1.2.0","1.2.0b1","1.2.1","1.2.2","1.3.0","1.4.0","1.4.1","1.4.2","1.5.0","1.5.1","2.0.0","2.0.0b1","2.0.0b2","2.0.0b3","2.0.0rc1","2.0.0rc2","2.0.0rc3","2.0.0rc4","2.0.0rc5","2.0.1","2.0.2","2.1.0","2.1.1","2.2.0","2.2.1","2.2.2","2.3.0","2.3.1","3.0.0","3.0.0b1","3.1.0","3.1.1","4.0.0","4.0.0b1","4.0.0b2","4.0.1","4.0.2","4.1.0","4.1.1","4.1.2","4.1.3","4.1.4","4.1.5","4.1.6","5.0.0","5.0.0b1","5.0.0b2","5.1.0","5.2.0","5.2.1","5.3.0","5.3.0rc0","5.4.0","5.4.1","5.4.2","5.4.3"]},{"source":"osv","ecosystem":"Ubuntu:22.04:LTS","package":"jupyterhub","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.0.0+ds1-1","2.0.0+ds1-2"]},{"source":"osv","ecosystem":"Ubuntu:24.04:LTS","package":"jupyterhub","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.0.0+ds1-1"]},{"source":"osv","ecosystem":"Ubuntu:25.10","package":"jupyterhub","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["5.2.1+ds1-2","5.2.1+ds1-3","5.2.1+ds1-4"]},{"source":"osv","ecosystem":"Ubuntu:26.10","package":"jupyterhub","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["5.2.1+ds1-4","5.2.1+ds1-5"]},{"source":"osv","ecosystem":"Ubuntu:26.04:LTS","package":"jupyterhub","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["5.2.1+ds1-4"]}],"products":[{"vendor":"jupyter","product":"jupyterhub"},{"vendor":"jupyterhub","product":"jupyterhub"}],"references":[{"url":"https://github.com/jupyterhub/jupyterhub/security/advisories/GHSA-3vff-hjqv-m7h8","tags":["x_refsource_CONFIRM","Mitigation","Vendor Advisory","advisory","web","report"]},{"url":"https://github.com/jupyterhub/jupyterhub/releases/tag/5.4.4","tags":["x_refsource_MISC","Product","web","report"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-33709","tags":["web","advisory"]},{"url":"https://github.com/advisories/GHSA-3vff-hjqv-m7h8"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/33xxx/CVE-2026-33709.json","tags":["advisory"]},{"url":"https://security-tracker.debian.org/tracker/CVE-2026-33709","tags":["advisory"]},{"url":"https://github.com/jupyterhub/jupyterhub","tags":["package"]},{"url":"https://ubuntu.com/security/CVE-2026-33709","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-33709","tags":["report"]}],"sources":{"cve":[{"id":"CVE-2026-33709","title":"JupyterHub has an Open Redirect Vulnerability","description":"JupyterHub is software that allows one to create a multi-user server for Jupyter notebooks. Prior to version 5.4.4, an open redirect vulnerability in JupyterHub allows attackers to construct links which, when clicked, take users to the JupyterHub login page, after which they are sent to an arbitrary attacker-controlled site outside JupyterHub instead of a JupyterHub page, bypassing JupyterHub's check to prevent this. This issue has been patched in version 5.4.4.","status":"published","published":"2026-04-03T22:00:46.703Z","modified":"2026-04-06T17:33:47.412Z","cvss":[{"version":"4.0","score":5.1,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N","level":"medium","assessor":"cna"}],"cwes":["CWE-601"],"updated_at":"2026-11-02T14:20:08.009733Z"}],"euvd":[{"id":"EUVD-2026-18880","description":"JupyterHub is software that allows one to create a multi-user server for Jupyter notebooks. Prior to version 5.4.4, an open redirect vulnerability in JupyterHub allows attackers to construct links which, when clicked, take users to the JupyterHub login page, after which they are sent to an arbitrary attacker-controlled site outside JupyterHub instead of a JupyterHub page, bypassing JupyterHub's check to prevent this. This issue has been patched in version 5.4.4.","status":"published","published":"2026-04-03T22:00:46Z","modified":"2026-04-06T17:33:47Z","cvss":[{"version":"4.0","score":5.1,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N","level":"medium"}],"updated_at":"2026-11-02T19:25:15.794407Z"}],"ghsa":[{"id":"GHSA-3vff-hjqv-m7h8","title":"JupyterHub has an Open Redirect Vulnerability","description":"## Affected Version\n\nJupyterHub \u003c= 5.4.3\n\n## Impact\n\nAn open redirect vulnerability in JupyterHub \u003c=5.4.3 allows attackers to construct links which, when clicked, take users to the JupyterHub login page, after which they are sent to an arbitrary attacker-controlled site outside JupyterHub instead of a JupyterHub page, bypassing JupyterHub's check to prevent this.\n\n## Patches\n\nUpgrade to JupyterHub 5.4.4\n\n## Workarounds\n\nA deployment can apply filters on the Location header in a reverse proxy such as nginx/apache/traefik.","status":"published","published":"2026-04-03T21:36:07Z","modified":"2026-04-27T16:19:31Z","cvss":[{"version":"3.1","score":6.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","level":"medium"},{"version":"4.0","score":5.1,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N","level":"medium"}],"cwes":["CWE-601"],"updated_at":"2026-11-02T14:39:58.897998Z"}],"nvd":[{"id":"CVE-2026-33709","description":"JupyterHub is software that allows one to create a multi-user server for Jupyter notebooks. Prior to version 5.4.4, an open redirect vulnerability in JupyterHub allows attackers to construct links which, when clicked, take users to the JupyterHub login page, after which they are sent to an arbitrary attacker-controlled site outside JupyterHub instead of a JupyterHub page, bypassing JupyterHub's check to prevent this. This issue has been patched in version 5.4.4.","status":"published","published":"2026-04-03T22:16:26.657Z","modified":"2026-07-24T22:10:00.14Z","cvss":[{"version":"4.0","score":5.1,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"medium","assessor":"secondary"},{"version":"3.1","score":6.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","level":"medium","assessor":"primary"}],"cwes":["CWE-601"],"updated_at":"2026-11-02T14:12:13.1424Z"}],"osv":[{"id":"CVE-2026-33709","title":"JupyterHub has an Open Redirect Vulnerability","description":"JupyterHub is software that allows one to create a multi-user server for Jupyter notebooks. Prior to version 5.4.4, an open redirect vulnerability in JupyterHub allows attackers to construct links which, when clicked, take users to the JupyterHub login page, after which they are sent to an arbitrary attacker-controlled site outside JupyterHub instead of a JupyterHub page, bypassing JupyterHub's check to prevent this. This issue has been patched in version 5.4.4.","status":"published","published":"2026-04-03T22:00:46.703Z","modified":"2026-10-28T02:30:35.118485595Z","cvss":[{"version":"4.0","score":5.1,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N","level":"medium"}],"cwes":["CWE-601"],"updated_at":"2026-11-02T15:45:01.896044Z"},{"id":"DEBIAN-CVE-2026-33709","description":"JupyterHub is software that allows one to create a multi-user server for Jupyter notebooks. Prior to version 5.4.4, an open redirect vulnerability in JupyterHub allows attackers to construct links which, when clicked, take users to the JupyterHub login page, after which they are sent to an arbitrary attacker-controlled site outside JupyterHub instead of a JupyterHub page, bypassing JupyterHub's check to prevent this. This issue has been patched in version 5.4.4.","status":"published","published":"2026-04-03T22:16:26.657Z","modified":"2026-10-01T03:03:10.477013977Z","cvss":[{"version":"3.1","score":6.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","level":"medium"}],"updated_at":"2026-11-02T15:45:54.587575Z"},{"id":"GHSA-3vff-hjqv-m7h8","title":"JupyterHub has an Open Redirect Vulnerability","description":"## Affected Version\n\nJupyterHub \u003c= 5.4.3\n\n## Impact\n\nAn open redirect vulnerability in JupyterHub \u003c=5.4.3 allows attackers to construct links which, when clicked, take users to the JupyterHub login page, after which they are sent to an arbitrary attacker-controlled site outside JupyterHub instead of a JupyterHub page, bypassing JupyterHub's check to prevent this.\n\n## Patches\n\nUpgrade to JupyterHub 5.4.4\n\n## Workarounds\n\nA deployment can apply filters on the Location header in a reverse proxy such as nginx/apache/traefik.","status":"published","published":"2026-04-03T21:36:07Z","modified":"2026-07-13T07:26:28.413653255Z","cvss":[{"version":"3.1","score":6.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","level":"medium"},{"version":"4.0","score":5.1,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N","level":"medium"}],"cwes":["CWE-601"],"updated_at":"2026-11-02T15:46:36.092962Z"},{"id":"PYSEC-2026-2188","description":"JupyterHub is software that allows one to create a multi-user server for Jupyter notebooks. Prior to version 5.4.4, an open redirect vulnerability in JupyterHub allows attackers to construct links which, when clicked, take users to the JupyterHub login page, after which they are sent to an arbitrary attacker-controlled site outside JupyterHub instead of a JupyterHub page, bypassing JupyterHub's check to prevent this. This issue has been patched in version 5.4.4.","status":"published","published":"2026-04-03T22:16:26.657Z","modified":"2026-07-13T07:26:28.413653255Z","cvss":[{"version":"3.1","score":6.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","level":"medium"}],"updated_at":"2026-11-02T15:52:55.537808Z"},{"id":"UBUNTU-CVE-2026-33709","description":"JupyterHub is software that allows one to create a multi-user server for Jupyter notebooks. Prior to version 5.4.4, an open redirect vulnerability in JupyterHub allows attackers to construct links which, when clicked, take users to the JupyterHub login page, after which they are sent to an arbitrary attacker-controlled site outside JupyterHub instead of a JupyterHub page, bypassing JupyterHub's check to prevent this. This issue has been patched in version 5.4.4.","status":"published","published":"2026-04-03T22:16:00Z","modified":"2026-10-17T12:58:11.040331179Z","cvss":[{"version":"4.0","score":5.1,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N","level":"medium"},{"version":"3.1","score":6.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","level":"medium"}],"updated_at":"2026-11-02T16:56:16.036833Z"},{"id":"BIT-jupyterhub-2026-33709","title":"JupyterHub has an Open Redirect Vulnerability","description":"JupyterHub is software that allows one to create a multi-user server for Jupyter notebooks. Prior to version 5.4.4, an open redirect vulnerability in JupyterHub allows attackers to construct links which, when clicked, take users to the JupyterHub login page, after which they are sent to an arbitrary attacker-controlled site outside JupyterHub instead of a JupyterHub page, bypassing JupyterHub's check to prevent this. This issue has been patched in version 5.4.4.","status":"published","published":"2026-04-08T08:40:42.508Z","modified":"2026-09-08T08:48:23.845625588Z","updated_at":"2026-11-02T15:28:31.782692Z"}]}}