{"cve":"CVE-2020-26275","nvd":{"published":"2020-12-21T18:15:15.353","modified":"2026-06-17T03:07:58.660","status":"Modified","description":"The Jupyter Server provides the backend (i.e. the core services, APIs, and REST endpoints) for Jupyter web applications like Jupyter notebook, JupyterLab, and Voila. In Jupyter Server before version 1.1.1, an open redirect vulnerability could cause the jupyter server to redirect the browser to a different malicious website. All 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. This is fixed in jupyter_server 1.1.1. If upgrade is not available, a workaround can be to run your server on a url prefix: \"jupyter server --ServerApp.base_url=/jupyter/\".","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","score":6.1},"cwes":["CWE-601"],"references":["https://advisory.checkmarx.net/advisory/CX-2020-4291","https://github.com/jupyter-server/jupyter_server/commit/85e4abccf6ea9321d29153f73b0bd72ccb3a6bca","https://github.com/jupyter-server/jupyter_server/security/advisories/GHSA-9f66-54xg-pc2c","https://pypi.org/project/jupyter-server/","https://advisory.checkmarx.net/advisory/CX-2020-4291"],"products":["jupyter:jupyter_server"],"source":"nvd","synced_at":"2026-10-19T21:12:09.559580076+00:00"},"epss":{"cve":"CVE-2020-26275","score":0.01373,"percentile":0.7198,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-9f66-54xg-pc2c","url":"https://osv.dev/vulnerability/GHSA-9f66-54xg-pc2c","summary":"Jupyter Server open redirect vulnerability","modified":"2026-07-09T16:56:16.793000806Z","packages":[{"ecosystem":"PyPI","name":"jupyter-server","purl":"pkg:pypi/jupyter-server","ranges":["<1.1.1"],"fixed":["1.1.1"]}]},{"id":"PYSEC-2020-50","url":"https://osv.dev/vulnerability/PYSEC-2020-50","summary":"","modified":"2026-07-09T16:56:16.793000806Z","packages":[{"ecosystem":"PyPI","name":"jupyter-server","purl":"pkg:pypi/jupyter-server","ranges":["<1.1.1"],"fixed":["1.1.1"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}