CVE-2020-26232 Open redirect in Jupyter Server

What is CVE-2020-26232?

CVE-2020-26232 is a medium-severity vulnerability in jupyter_server, published on 24 Nov 2020. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

Official description

Jupyter Server before version 1.0.6 has an Open redirect vulnerability. A maliciously crafted link to a jupyter server could redirect the browser to a different website. All jupyter servers are technically affected, however, these maliciously crafted links can only be reasonably made for known jupyter server hosts. A link to your jupyter server may appear safe, but ultimately redirect to a spoofed server on the public internet.

Weakness: CWE-601

Which versions are affected by CVE-2020-26232?

3 open source packages ship an affected version, including jupyter-server. It affects 1 product.

Products include Jupyter Jupyter Server.

How do I fix CVE-2020-26232?

Upgrade jupyter-server to 1.0.6 or later.

Is CVE-2020-26232 being exploited?

There is no known exploitation of CVE-2020-26232 in the wild and no public exploit code.

Other vulnerabilities in jupyter_server

• CVE-2026-44727 Jupyter Server: Stored XSS in `NbconvertFileHandler` / `NbconvertPostHandler` via missing `sandbox` CSP Critical 9.3
• CVE-2026-35397 jupyter-server path traversal allows access to sibling directories sharing root_dir name prefix High 7.6
• CVE-2026-40110 jupyter-server CORS origin validation bypass via unanchored regex in allow_origin_pat High 7.6
• CVE-2026-40934 jupyter-server authentication cookies remain valid after password reset due to static cookie secret High 7.6
• CVE-2024-35178 Jupyter server on Windows discloses Windows user password hash High 7.5

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as DEBIAN-CVE-2020-26232, GHSA-grfj-wjv9-4f9v, PYSEC-2020-234, openSUSE-SU-2024:11233-1, openSUSE-SU-2024:14143-1.