CVE-2026-44182 describes a critical YAML injection vulnerability in jupyter-server's enterprise_gateway component. In versions before 3.3.0, untrusted environment variables (e.g., KERNEL_XXX) are interpolated into Kubernetes manifests without YAML-aware escaping. This enables attackers to inject new YAML fields, overwrite existing ones (such as securityContext keys), and insert document boundaries to create multiple Kubernetes resources, potentially including privileged pods. The vulnerability stems from the use of Jinja2 templates that incorporate kernel-related environment variables without proper sanitization. The vulnerability is fixed in version 3.3.0.

Successful exploitation allows an unauthenticated attacker to perform YAML injection via environment variables, leading to the creation or modification of Kubernetes resources. This can result in privilege escalation by creating privileged pods or altering security contexts, severely compromising cluster security. The CVSS 4.0 score of 10 reflects the critical nature and ease of exploitation without user interaction or privileges.

Upgrade to jupyter-server enterprise_gateway version 3.3.0 or later, where this YAML injection vulnerability is fixed. Since no official patch link or advisory is provided, verify the upgrade path with the vendor's official releases. Until upgraded, avoid using untrusted environment variables in Kubernetes manifest templates or apply manual YAML escaping if feasible. Patch status is not explicitly confirmed in the advisory data, so check the vendor advisory for current remediation guidance.