CVE-2026-40110
Publication date 5 May 2026
Last updated 13 May 2026
Ubuntu priority
Description
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.
Status
| Package | Ubuntu Release | Status |
|---|---|---|
| jupyter-server | 26.04 LTS resolute |
Needs evaluation
|
| 25.10 questing |
Needs evaluation
|
|
| 24.04 LTS noble |
Needs evaluation
|
|
| 22.04 LTS jammy |
Needs evaluation
|
References
Other references
- https://www.cve.org/CVERecord?id=CVE-2026-40110
- https://github.com/jupyter-server/jupyter_server/security/advisories/GHSA-24qx-w28j-9m6p
- https://github.com/jupyter-server/jupyter_server/pull/603
- https://github.com/jupyter-server/jupyter_server/commit/057869a327c46730afede3eab0ca2d2e3e74acea (v2.18.0)
- https://github.com/jupyter-server/jupyter_server/commit/49b34392feaa97735b3b777e3baf8f22f2a14ed8 (v2.18.0)