{"id":"GHSA-9f66-54xg-pc2c","summary":"Jupyter Server open redirect vulnerability","details":"### Impact\n_What kind of vulnerability is it? Who is impacted?_\n\nOpen redirect vulnerability - a maliciously crafted link to a jupyter server could redirect the browser to a different website.\n\nAll jupyter servers running without a base_url prefix are technically affected, however, these maliciously crafted links can only be reasonably made for known jupyter server hosts. A link to your jupyter server may *appear* safe, but ultimately redirect to a spoofed server on the public internet. This same vulnerability was patched in upstream notebook v5.7.8.\n\n### Patches\n\n_Has the problem been patched? What versions should users upgrade to?_\n\nPatched in jupyter_server 1.1.1. If upgrade is not available, a workaround can be to run your server on a url prefix:\n\n```\njupyter server --ServerApp.base_url=/jupyter/\n```\n\n### References\n\n[OWASP page on open redirects](https://cheatsheetseries.owasp.org/cheatsheets/Unvalidated_Redirects_and_Forwards_Cheat_Sheet.html)\n\n### For more information\n\nIf you have any questions or comments about this advisory, or vulnerabilities to report, please email our security list [security@ipython.org](mailto:security@ipython.org).\n\nCredit: Yaniv Nizry from CxSCA group at Checkmarx","aliases":["CVE-2020-26275","PYSEC-2020-50"],"modified":"2026-07-09T16:56:16.793000806Z","published":"2020-12-21T18:01:41Z","database_specific":{"github_reviewed":true,"github_reviewed_at":"2020-12-21T18:00:51Z","nvd_published_at":"2020-12-21T18:15:00Z","cwe_ids":["CWE-601"],"severity":"MODERATE"},"references":[{"type":"WEB","url":"https://github.com/jupyter-server/jupyter_server/security/advisories/GHSA-9f66-54xg-pc2c"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2020-26275"},{"type":"WEB","url":"https://github.com/jupyter-server/jupyter_server/commit/85e4abccf6ea9321d29153f73b0bd72ccb3a6bca"},{"type":"WEB","url":"https://advisory.checkmarx.net/advisory/CX-2020-4291"},{"type":"PACKAGE","url":"https://github.com/jupyter-server/jupyter_server"},{"type":"WEB","url":"https://github.com/pypa/advisory-database/tree/main/vulns/jupyter-server/PYSEC-2020-346.yaml"},{"type":"WEB","url":"https://github.com/pypa/advisory-database/tree/main/vulns/jupyter-server/PYSEC-2020-50.yaml"},{"type":"WEB","url":"https://pypi.org/project/jupyter-server"}],"affected":[{"package":{"name":"jupyter-server","ecosystem":"PyPI","purl":"pkg:pypi/jupyter-server"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.1.1"}]}],"versions":["0.0.0","0.0.1","0.0.2","0.0.3","0.0.4","0.0.5","0.1.0","0.1.1","0.2.0","0.2.1","0.3.0","1.0.0","1.0.0rc0","1.0.0rc1","1.0.0rc10","1.0.0rc11","1.0.0rc12","1.0.0rc13","1.0.0rc14","1.0.0rc15","1.0.0rc16","1.0.0rc2","1.0.0rc3","1.0.0rc4","1.0.0rc5","1.0.0rc6","1.0.0rc7","1.0.0rc8","1.0.0rc9","1.0.1","1.0.10","1.0.11","1.0.2","1.0.3","1.0.4","1.0.5","1.0.6","1.0.7","1.0.8","1.0.9","1.1.0"],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2020/12/GHSA-9f66-54xg-pc2c/GHSA-9f66-54xg-pc2c.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N"},{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N"}]}