7.6

CVE-2026-40110

jupyter-server CORS origin validation bypass via unanchored regex in allow_origin_pat

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() only anchors at the start of the string and does not require a full match, a pattern intended to match only a trusted domain (e.g., trusted.example.com) will also match any origin that begins with that domain followed by additional characters (e.g., trusted.example.com.evil.com). An attacker who controls such a domain can bypass the CORS origin restriction and make cross-origin requests to the Jupyter Server API from an untrusted site. This issue has been fixed in version 2.18.0.
Daten sind bereitgestellt durch National Vulnerability Database (NVD)
Jupyter ≫ Jupyter Server Version < 2.18.0
Zu dieser CVE wurde keine Warnung gefunden.
EPSS Metriken
Typ Quelle Score Percentile
EPSS FIRST.org 0.33% 0.25
CVSS Metriken
Quelle Base Score Exploit Score Impact Score Vector String
nvd@nist.gov 7.3 2.1 5.2
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N
security-advisories@github.com 7.6 0 0
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:L/SC:L/SI:L/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
0b0ca135-0b70-47e7-9f44-1890c2a1c46c 7.1 2.8 4.2
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:L/A:N
CWE-625 Permissive Regular Expression

The product uses a regular expression that does not sufficiently restrict the set of allowed values.

CWE-777 Regular Expression without Anchors

The product uses a regular expression to perform neutralization, but the regular expression is not anchored and may allow malicious or malformed data to slip through.

https://github.com/jupyter-server/jupyter_server/commit/057869a327c46730afede3eab0ca2d2e3e74acea
Patch
https://github.com/jupyter-server/jupyter_server/commit/49b34392feaa97735b3b777e3baf8f22f2a14ed8
Patch
https://github.com/jupyter-server/jupyter_server/pull/603
Issue Tracking
https://github.com/jupyter-server/jupyter_server/security/advisories/GHSA-24qx-w28j-9m6p
Patch
Vendor Advisory
Mitigation
https://access.redhat.com/security/cve/CVE-2026-40110
https://bugzilla.redhat.com/show_bug.cgi?id=2466912
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-40110.json