{"cve":"CVE-2024-35225","nvd":{"published":"2024-06-11T22:15:09.520","modified":"2026-06-17T07:34:34.693","status":"Analyzed","description":"Jupyter Server Proxy allows users to run arbitrary external processes alongside their notebook server and provide authenticated web access to them. Versions of 3.x prior to 3.2.4 and 4.x prior to 4.2.0 have a reflected cross-site scripting (XSS) issue. The `/proxy` endpoint accepts a `host` path segment in the format `/proxy/<host>`. When this endpoint is called with an invalid `host` value, `jupyter-server-proxy` replies with a response that includes the value of `host`, without sanitization [2]. A third-party actor can leverage this by sending a phishing link with an invalid `host` value containing custom JavaScript to a user. When the user clicks this phishing link, the browser renders the response of `GET /proxy/<host>`, which runs the custom JavaScript contained in `host` set by the actor. As any arbitrary JavaScript can be run after the user clicks on a phishing link, this issue permits extensive access to the user's JupyterLab instance for an actor. Patches are included in versions 4.2.0 and 3.2.4. As a workaround, server operators who are unable to upgrade can disable the `jupyter-server-proxy` extension.","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-79","CWE-116"],"references":["https://github.com/jupyterhub/jupyter-server-proxy/blob/62a290f08750f7ae55a0c29ca339c9a39a7b2a7b/jupyter_server_proxy/handlers.py#L328","https://github.com/jupyterhub/jupyter-server-proxy/commit/7abc9dc5bbb0b4b440548a5375261b8b8192fc22","https://github.com/jupyterhub/jupyter-server-proxy/commit/ff78128087e73fb9d0909e1366f8bf051e8ea878","https://github.com/jupyterhub/jupyter-server-proxy/security/advisories/GHSA-fvcq-4x64-hqxr","https://github.com/jupyterhub/jupyter-server-proxy/blob/62a290f08750f7ae55a0c29ca339c9a39a7b2a7b/jupyter_server_proxy/handlers.py#L328"],"products":["jupyter:jupyter_server_proxy"],"source":"nvd","synced_at":"2026-10-19T21:51:20.603330631+00:00"},"epss":{"cve":"CVE-2024-35225","score":0.00446,"percentile":0.38816,"date":"2026-11-01"},"kev":null,"osv":[{"id":"GHSA-fvcq-4x64-hqxr","url":"https://osv.dev/vulnerability/GHSA-fvcq-4x64-hqxr","summary":"Jupyter Server Proxy has a reflected XSS issue in host parameter","modified":"2026-06-10T17:14:15.885916313Z","packages":[{"ecosystem":"PyPI","name":"jupyter-server-proxy","purl":"pkg:pypi/jupyter-server-proxy","ranges":[">=3.0.0 <3.2.4"],"fixed":["3.2.4"]},{"ecosystem":"PyPI","name":"jupyter-server-proxy","purl":"pkg:pypi/jupyter-server-proxy","ranges":[">=4.0.0 <4.2.0"],"fixed":["4.2.0"]}]},{"id":"PYSEC-2024-236","url":"https://osv.dev/vulnerability/PYSEC-2024-236","summary":"","modified":"2026-06-10T17:14:18.907740365Z","packages":[{"ecosystem":"PyPI","name":"jupyter-server-proxy","purl":"pkg:pypi/jupyter-server-proxy","ranges":[">=3.0.0 <3.2.4",">=4.1.2 <4.2.0"],"fixed":["3.2.4","4.2.0"]}]}],"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."]}