---
id: CVE-2023-40170
aliases:
  - GHSA-64x5-55rw-9974
  - PYSEC-2023-157
title: cross-site inclusion (XSSI) of files in jupyter-server
summary: cross-site inclusion (XSSI) of files in jupyter-server
severity: medium
cvss: 4.6
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N'
vendor: jupyter-server
product: jupyter-server
ecosystem: pip
affected:
  - jupyter-server < 2.7.2
patched:
  - jupyter-server 2.7.2
published: '2023-08-29'
updated: '2026-09-10'
sourceUpdated: '2026-09-10T03:49:57.417478394Z'
source: OSV
sourceUrl: 'https://osv.dev/vulnerability/GHSA-64x5-55rw-9974'
references:
  - url: >-
      https://github.com/jupyter-server/jupyter_server/security/advisories/GHSA-64x5-55rw-9974
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2023-40170'
  - url: >-
      https://github.com/jupyter-server/jupyter_server/commit/87a4927272819f0b1cae1afa4c8c86ee2da002fd
  - url: 'https://github.com/jupyter-server/jupyter_server'
  - url: >-
      https://github.com/pypa/advisory-database/tree/main/vulns/jupyter-server/PYSEC-2023-157.yaml
  - url: >-
      https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/NRP7DNZYVOIA4ZB3U3ZWKTFZEPYWNGCQ
  - url: >-
      https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/XDKQAWQN6SQTOVACZNXYKEHWQXGG4DOF
tags:
  - osv
  - pip
epss: 0.00623
epssPercentile: 0.47595
ingestedAt: '2026-09-12T03:13:01.664Z'
---

## Overview

### Impact

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".

### Patches

Jupyter Server 2.7.2

### Workarounds

Use lower performance `--ContentsManager.files_handler_class=jupyter_server.files.handlers.FilesHandler`, which implements the correct checks.

### References

Upstream patch for CVE-2019-9644 was not applied completely, leaving part of the vulnerability open.

Vulnerability reported by Tim Coen via the [bug bounty program](https://app.intigriti.com/programs/jupyter/jupyter/detail) [sponsored by the European Commission](https://commission.europa.eu/news/european-commissions-open-source-programme-office-starts-bug-bounties-2022-01-19_en) and hosted on the [Intigriti platform](https://www.intigriti.com/).

## Affected packages

- `jupyter-server < 2.7.2`

## Remediation

Upgrade to a patched release:

- `jupyter-server 2.7.2`