CVE-2026-40110
7.3 · HIGHOverview
CVE-2026-40110 is a high-severity vulnerability affecting jupyter jupyter_server. It was published on May 5, 2026 and has a CVSS 3.1 base score of 7.3 (HIGH).
This vulnerability has a CVSS 3.1 base score of 7.3, rated HIGH. It can be exploited remotely over the network. Some level of privileges is required for exploitation.
Technical 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.
Remediation
Check the references section for vendor advisories and patches from jupyter. Update jupyter_server to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
Affected Products
| Vendor | Product | Versions | Status |
|---|---|---|---|
| jupyter | jupyter_server | >= 0, < 2.18.0 | Affected |
References
Frequently Asked Questions
What is CVE-2026-40110?
CVE-2026-40110 is a high-severity vulnerability affecting jupyter jupyter_server. It was published on May 5, 2026 and has a CVSS 3.1 base score of 7.3 (HIGH).
How severe is CVE-2026-40110?
This vulnerability has a CVSS 3.1 base score of 7.3, rated HIGH. It can be exploited remotely over the network. Some level of privileges is required for exploitation.
How do I fix or remediate CVE-2026-40110?
Check the references section for vendor advisories and patches from jupyter. Update jupyter_server to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2026-40110?
CyberStrike's AI-powered security agents can automatically detect CVE-2026-40110 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.
How CyberStrike Helps
AI agents map your attack surface to find vulnerabilities like this one.
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