Cross-Origin Request Forgery in Jupyter Server Versions by Project Jupyter
CVE-2026-40110

7.6HIGH

Key Information:

Vendor

Jupyter-server

Status
Jupyter Server
Vendor
CVE Published:
5 May 2026

What is CVE-2026-40110?

Jupyter Server versions up to 2.17.0 are susceptible to a Cross-Origin Request Forgery (CORS) vulnerability due to inadequate Origin header validation. The use of Python's re.match() for validation allows malicious domains that start with a trusted origin to bypass CORS restrictions, enabling cross-origin requests to the Jupyter Server API from unauthorized sources. This security concern can lead to potential data leaks or unauthorized actions being performed within the server environment. The issue has been addressed in version 2.18.0.

Affected Version(s)

jupyter_server <= 2.17.0

References

https://github.com/jupyter-server/jupyter_server/security...
x_refsource_CONFIRM
https://github.com/jupyter-server/jupyter_server/pull/603
x_refsource_MISC
https://github.com/jupyter-server/jupyter_server/commit/0...
x_refsource_MISC

CVSS V4

Score:
7.6
Severity:
HIGH
Confidentiality:
High
Integrity:
High
Availability:
Low
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
Physical
Privileges Required:
Undefined
User Interaction:
Unknown

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.