How severe is CVE-2023-40170?

CVE-2023-40170 has a CVSS score of 4.6/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2023-40170?

CVE-2023-40170 affects the following packages: jupyter-server (PyPI). Ecosystems affected: PyPI.

How do I fix CVE-2023-40170?

Update jupyter-server to 2.7.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-40170 is resolved across your whole dependency graph.

How do I detect CVE-2023-40170 in my PyPI dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for jupyter-server. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

How do I mitigate CVE-2023-40170 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

How does O3 Security protect against CVE-2023-40170?

O3 pinpoints whether CVE-2023-40170 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is CVE-2023-40170 actively exploited in the wild?

No public exploit code has been indexed for CVE-2023-40170 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2023-40170?

CVE-2023-40170 has an EPSS (Exploit Prediction Scoring System) score of 0.5%, placing it in the 41th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

When was CVE-2023-40170 published, and has it been updated?

CVE-2023-40170 was published on August 28, 2023 and was last updated on April 10, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐍 PyPI

CVE-2023-40170

MEDIUM

cross-site inclusion (XSSI) of files in jupyter-server

Also known asGHSA-64x5-55rw-9974PYSEC-2023-157

Published

Aug 28, 2023

Updated

Apr 10, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

EPSS Exploitation Probability

via FIRST.org ↗

0.5%probability of exploitation in next 30 days

Lower Risk41th percentile-0.18%

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Blast Radius

1 pkg affected

🐍jupyter-server

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.

Description

jupyter-server is the backend for Jupyter web applications. Improper cross-site credential checks on /files/ URLs could allow exposure of certain file contents, or accessing files when opening untrusted files via "Open image in new tab". This issue has been addressed in commit 87a49272728 which has been included in release 2.7.2. Users are advised to upgrade. Users unable to upgrade may use the lower performance --ContentsManager.files_handler_class=jupyter_server.files.handlers.FilesHandler, which implements the correct checks.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐍PyPI	`jupyter-server`	all versions	2.7.2

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for jupyter-server. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update jupyter-server to 2.7.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-40170 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2023-40170 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to CVE-2023-40170. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

jupyter-server is the backend for Jupyter web applications. Improper cross-site credential checks on `/files/` URLs could allow exposure of certain file contents, or accessing files when opening untrusted files via "Open image in new tab". This issue has been addressed in commit `87a49272728` which has been included in release `2.7.2`. Users are advised to upgrade. Users unable to upgrade may use the lower performance `--ContentsManager.files_handler_class=jupyter_server.files.handlers.FilesHandler`, which implements the correct checks.

O3 Security · Impact-Aware SCA

Is CVE-2023-40170 in your dependencies?

O3 detects CVE-2023-40170 across PyPI dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

Scan my dependencies How O3 SCA works