{"cve":"CVE-2025-23205","nvd":{"published":"2025-01-17T21:15:11.850","modified":"2026-06-17T08:52:37.530","status":"Deferred","description":"nbgrader is a system for assigning and grading notebooks. Enabling frame-ancestors: 'self' grants any JupyterHub user the ability to extract formgrader content by sending malicious links to users with access to formgrader, at least when using the default JupyterHub configuration of `enable_subdomains = False`. #1915 disables a protection which would allow user Alice to craft a page embedding formgrader in an IFrame. If Bob visits that page, his credentials will be sent and the formgrader page loaded. Because Alice's page is on the same Origin as the formgrader iframe, Javasript on Alice's page has _full access_ to the contents of the page served by formgrader using Bob's credentials. This issue has been addressed in release 0.9.5 and all users are advised to upgrade. Users unable to upgrade may disable `frame-ancestors: self`, or enable per-user and per-service subdomains with `JupyterHub.enable_subdomains = True` (then even if embedding in an IFrame is allowed, the host page does not have access to the contents of the frame).","cvss_v4":{"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N","score":6.9},"cvss_v3":null,"cwes":["CWE-668"],"references":["https://github.com/jupyter/nbgrader/commit/73e137511ac1dc02e95790d4fd6d4d88dab42325","https://github.com/jupyter/nbgrader/pull/1915","https://github.com/jupyter/nbgrader/security/advisories/GHSA-fcr8-4r9f-r66m","https://jupyterhub.readthedocs.io/en/stable/explanation/websecurity.html#:~:text=frame-ancestors"],"products":[],"source":"nvd","synced_at":"2026-10-19T21:58:20.756570362+00:00"},"epss":{"cve":"CVE-2025-23205","score":0.0049,"percentile":0.42163,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-fcr8-4r9f-r66m","url":"https://osv.dev/vulnerability/GHSA-fcr8-4r9f-r66m","summary":"nbgrader's `frame-ancestors: self` grants all users access to formgrader","modified":"2026-07-07T17:56:43.444278742Z","packages":[{"ecosystem":"PyPI","name":"nbgrader","purl":"pkg:pypi/nbgrader","ranges":[">=0.9.4 <0.9.5"],"fixed":["0.9.5"]}]},{"id":"PYSEC-2026-1692","url":"https://osv.dev/vulnerability/PYSEC-2026-1692","summary":"nbgrader's `frame-ancestors: self` grants all users access to formgrader","modified":"2026-07-07T17:47:07.133835659Z","packages":[{"ecosystem":"PyPI","name":"nbgrader","purl":"pkg:pypi/nbgrader","ranges":[">=0.9.4 <0.9.5"],"fixed":["0.9.5"]}]}],"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."]}