Regular Expression without Anchors in Jupyter Server - CVE-2026-40110
Published: May 5, 2026
Vulnerability identifier: #VU130161
CSH Severity: Medium
CVSS v4: 7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-40110
CWE-ID: CWE-777
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to disclose sensitive information and modify data.
The vulnerability exists due to regular expression without anchors in the allow_origin_pat Origin header validation when validating cross-origin requests. A remote attacker can use a controlled domain that prefixes a trusted origin to bypass validation and disclose sensitive information and modify data.
User interaction is required.
Affected software
Jupyter Server
How to mitigate CVE-2026-40110
Install security update from vendor's website.
Jupyter Server - update to 2.18.0