What is CVE-2020-36191?

CVE-2020-36191 is a medium-severity vulnerability in Jupyter Jupyterhub, classified under Cross-Site Request Forgery (CSRF). CVSS score: 4.5/10. Published 2021-01-13.

How severe is CVE-2020-36191?

Medium severity. CVSS v3 base score is 4.5 out of 10.

CSRF in Jupyter Jupyterhub

CVE-2020-36191

JupyterHub 1.1.0 allows CSRF in the admin panel via a request that lacks an _xsrf field, as demonstrated by a /hub/api/user request (to add or remove a user account).

Vulnerability class: CSRF (Cross-Site Request Forgery)

Published 2021-01-13 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 4.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:N/I:H/A:N.

EPSS exploit prediction

EPSS: 0.005 (42.2th percentile), scored 2026-10-19.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 42nd percentile — 42.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.005 · newest: 0.005 · change: +0.000

Affected products

Jupyter Jupyterhub — versions 1.1.0

Weakness classification (CWE)

CWE-352 — Cross-Site Request Forgery (CSRF)

References

github.com/jupyterhub/jupyterhub/issues/3304 (Exploit, Third Party Advisory)
github.com/jupyterhub/jupyterhub/releases (Third Party Advisory)

Frequently asked questions

What is CVE-2020-36191?: CVE-2020-36191 is a medium-severity vulnerability in Jupyter Jupyterhub, classified under Cross-Site Request Forgery (CSRF). CVSS score: 4.5/10. Published 2021-01-13.
How severe is CVE-2020-36191?: Medium severity. CVSS v3 base score is 4.5 out of 10.