Open redirect in Jupyter Notebook

Answer in brief

CVE-2020-26215 records a Medium severity (CVSS 4.4) vulnerability in Open redirect in Jupyter Notebook. The current sources do not mark it as known exploited. The current feed maps notebook (pypi). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Nov 18, 2020Updated Sep 10, 2026Source checked Sep 10, 2026First seen by HOL Sep 10, 2026Material review Sep 10, 2026

Upstream Advisory

Key facts

Risk: Medium · CVSS 4.4
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Available

Why this deserves its current priority

CVSS is 4.4. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps notebook (pypi). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
notebookpypi	>=0 <6.1.5	6.1.5

Recommended response

Check inventory. Check lockfiles and deployed manifests for notebook.
Review the reported fix. Update notebook to 6.1.5 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Nov 18, 2020
Evidence: source:osv:source_dates:source-dates:record
Source modified
Sep 10, 2026
Evidence: source:osv:source_dates:source-dates:record
First seen by HOL
Sep 10, 2026

Sources and claim methodology

Upstream source description

### Impact _What kind of vulnerability is it? Who is impacted?_ Open redirect vulnerability - a maliciously crafted link to a notebook server could redirect the browser to a different website. All notebook servers are technically affected, however, these maliciously crafted links can only be reasonably made for known notebook server hosts. A link to your notebook server may *appear* safe, but ultimately redirect to a spoofed server on the public internet. ### Patches _Has the problem been patched? What versions should users upgrade to?_ Patched in notebook 6.1.5 ### References [OWASP page on open redirects](https://cheatsheetseries.owasp.org/cheatsheets/Unvalidated_Redirects_and_Forwards_Cheat_Sheet.html) ### For more information If you have any questions or comments about this advisory, or vulnerabilities to report, please email our security list [[email protected]](mailto:[email protected]). Credit: zhuonan li of Alibaba Application Security Team

Quoted source text, attributed separately from HOL analysis.