Open Redirect Vulnerability in jupyter-server

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

5.3 · CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N · score source

EPSS

• CVE-2023-39968: 0.68% estimated exploitation activity in the next 30 days; percentile 52.46 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Impact Open Redirect Vulnerability. Maliciously crafted login links to known Jupyter Servers can cause successful login or an already logged-in session to be redirected to arbitrary sites, which should be restricted to Jupyter Server-served URLs. Patches Upgrade to Jupyter Server 2.7.2 Workarounds None. References Vulnerability reported by user davwwwx via the bug bounty program sponsored by the European Commission and hosted on the Intigriti platform. - https://blog.xss.am/2023/08/cve-2023-39968-jupyter-token-leak/

Published by the source

29 Aug 2023, 23:34 UTC

Last modified by the source

10 Sep 2026, 03:50 UTC

Source last checked

26 Oct 2026, 13:17 UTC

1. Revision 3 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-r726-vmfq-j9j3

2. Revision 2 · amended · 25 Oct 2026

   Reviewed OSV alias/range/CVSS4 correction; package source scopes and original publication preserved. No customer finding resolved.

3. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-r726-vmfq-j9j3

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# Patch Next advisory brief: CVE-2023-39968

Advisory: Open Redirect Vulnerability in jupyter-server
IDs: CVE-2023-39968, GHSA-r726-vmfq-j9j3
Record: https://patchnext.com/advisories/cve-2023-39968 (revision 3, source checked 26 Oct 2026, 13:17 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 5.3)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: jupyter-server 2.7.2. A vendor fix does not mean a deployment is fixed.

## Affected components
- PyPI jupyter-server: affected < 2.7.2; fixed in 2.7.2

## Suggested inspection (read-only)
- `python -m pip show jupyter-server`: prints the installed version. Run with the environment that serves production active.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on jupyter-server.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-r726-vmfq-j9j3 (OSV record GHSA-r726-vmfq-j9j3 lists affected ranges: PyPI jupyter-server >=0 <2.7.2 (fixed))
- Verified: https://github.com/advisories/GHSA-r726-vmfq-j9j3 (GitHub-reviewed advisory GHSA-r726-vmfq-j9j3 lists affected ranges: PyPI jupyter-server >=0 <2.7.2)

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