What is CVE-2025-23205?

CVE-2025-23205 is a high-severity security vulnerability in nbgrader (pip), affecting versions = 0.9.4. It is fixed in 0.9.5.

Which versions of nbgrader are affected by CVE-2025-23205?

nbgrader (pip) versions = 0.9.4 is affected.

Is there a fix for CVE-2025-23205?

Yes. CVE-2025-23205 is fixed in 0.9.5. Upgrade to this version or later.

Is CVE-2025-23205 exploitable, and should I be worried?

Whether CVE-2025-23205 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk.

What actually determines whether CVE-2025-23205 is exploitable, and how bad it is?

Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.

CVE-2025-23205 in nbgrader

Q: How do I fix CVE-2025-23205?

Upgrade nbgrader to 0.9.5 or later.

Summary

nbgrader's frame-ancestors: self grants all users access to formgrader

Workarounds

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).

References

JupyterHub documentation on why and when frame-ancestors: self is insecure, and why it was disabled by default: https://jupyterhub.readthedocs.io/en/stable/explanation/websecurity.html#:~:text=frame-ancestors

Impact

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.

Affected versions

nbgrader (= 0.9.4)

Security releases

nbgrader → 0.9.5 (pip)

Kodem intelligence

Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.

Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.

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Remediation advice

Upgrade nbgrader to 0.9.5 or later to resolve this vulnerability.

Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.

Frequently Asked Questions

What is CVE-2025-23205? CVE-2025-23205 is a high-severity security vulnerability in nbgrader (pip), affecting versions = 0.9.4. It is fixed in 0.9.5.
Which versions of nbgrader are affected by CVE-2025-23205? nbgrader (pip) versions = 0.9.4 is affected.
Is there a fix for CVE-2025-23205? Yes. CVE-2025-23205 is fixed in 0.9.5. Upgrade to this version or later.
Is CVE-2025-23205 exploitable, and should I be worried? Whether CVE-2025-23205 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
What actually determines whether CVE-2025-23205 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
How do I fix CVE-2025-23205? Upgrade nbgrader to 0.9.5 or later.