Vulnerability in Jupyter Jupyter_server

CVE-2026-40110

Jupyter Server is the backend for Jupyter web applications. In versions 2.17.0 and earlier, the Origin header validation uses Python's re.match() to check incoming origins against the allow_origin_pat configuration value. Because re.match(…

EPSS: 0.000 (1.8th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.3 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-40110?
CVE-2026-40110 is a high-severity vulnerability in Jupyter Jupyter_server, classified under CWE-777. CVSS score: 7.3/10. Published 2026-05-05.
How severe is CVE-2026-40110?
High severity. CVSS v3 base score is 7.3 out of 10.