By vendor

Jupyter vulnerabilities

Known CVEs affecting Jupyter products, prioritized by severity, with SEC.co remediation and detection guidance.

4 published vulnerabilities

• CVE-2026-6657HIGH 8.8

  A flaw in Jupyter Server allows attackers to bypass its cross-origin request (CORS) validation by exploiting how the software validates the `Origin` header. When administrators configure allowed origins using the `allow_origin_pat` setting, the validation logic uses a partial string match rather than a complete one. This means an attacker can craft a domain like `trusted.example.com.evil.com` that will pass validation meant only for `trusted.example.com`. The vulnerability affects versions 1.12.0 through 2.17.0 and impacts CORS headers, WebSocket connections, referer checking, and login redirects, potentially enabling phishing, code execution, and unauthorized access to APIs.

• CVE-2026-5422HIGH 8.1

  A flaw in Jupyter Server version 2.17.0 allows authenticated users to read and write files outside their intended directory boundaries. The vulnerability stems from an incomplete security check that fails to properly validate file path requests, allowing attackers to access sibling directories and potentially sensitive files in shared hosting environments. An attacker with login credentials can exploit this to breach confidentiality and integrity of data across directory structures that were meant to be isolated.

• CVE-2026-54528HIGH 7.1

  JupyterLab Git, a popular Git integration extension for JupyterLab notebooks, contains a path-matching flaw that allows authenticated users to bypass access restrictions on sensitive directories. By slightly altering the capitalization of URLs on case-insensitive filesystems (like Windows or macOS), an attacker can read files that administrators intended to exclude from access. This affects versions before 0.54.0 and requires authentication but no user interaction to exploit.

• CVE-2026-44727MEDIUM 5.4

  Jupyter Server versions before 2.20 contain a stored cross-site scripting (XSS) vulnerability in the notebook conversion feature. When a user opens a malicious notebook through the web interface, specially crafted HTML content in the notebook can execute arbitrary JavaScript in the browser with access to session cookies and the Jupyter API. An attacker who can get a user to open a prepared notebook—either by hosting it or tricking them into uploading it—can steal credentials, modify notebooks, or execute code on the Jupyter kernel itself. The vulnerability requires user interaction (opening the notebook) and authenticated access to Jupyter, which limits the immediate blast radius but poses significant risk in multi-user or shared research environments.