critical CVSS 10

CVE-2026-44181·Docker vulnerability

Jupyter Enterprise Gateway launches remote Jupyter Notebook kernels across distributed clusters like Apache Spark, Kubernetes, and Docker Swarm. In versions 2.0.0rc2 and above, prior to 3.3.0, the environment variables (KERNEL_XXX) used during the rendering of the Kubernetes manifest are vulnerable to Server Side Template Injection (SSTI). By including Jinja2 template expressions it is possible to execution Python code and OS Commands in the Enterprise Gateway service. The code can use or steal the Kubernetes service account token, which can steal Kubernetes secrets and be used to fully compromise the Kubernetes cluster by scheduling a privileged pod or a pod with a hostPath volume mount. This issue has been fixed in version 3.3.0.

Severity
critical
Software
Docker
Fixed in
3.3.0
Published
2026-07-16

Affected versions

From: 2.1.0

Until: 3.3.0

Fixed in: 3.3.0

How to fix this CVE

Upgrade Docker to version 3.3.0 or later to patch the Server Side Template Injection vulnerability in Jupyter Enterprise Gateway that allows remote code execution through malicious environment variables. Organizations running Docker versions 2.1.0 through 3.3.0 should prioritize this update, especially in Kubernetes environments where the service account token could be compromised.

sudo dnf update docker-ce

Defensia detects this vulnerability

How to check if you are affected

  1. Step 1: Check installed Docker version with 'docker --version' and compare against the affected range (2.1.0-3.3.0)
  2. Step 2: Verify if Jupyter Enterprise Gateway is deployed in your Docker environment using 'docker ps | grep -i jupyter' or 'docker images | grep -i jupyter'
  3. Step 3: Search container logs for suspicious Jinja2 template expressions in environment variables using 'docker logs {container_id} | grep -E "{{.*}}|{%.*%}"'
  4. Step 4: Confirm the patch by checking the Enterprise Gateway release version in running containers with 'docker inspect {container_id} | grep -i version' and verify it shows 3.3.0 or later

FAQ

What is CVE-2026-44181?

CVE-2026-44181 is a critical Server Side Template Injection flaw in Jupyter Enterprise Gateway that allows unauthenticated attackers to execute arbitrary Python and OS commands by injecting Jinja2 template expressions into environment variables used during Kubernetes manifest rendering.

Is CVE-2026-44181 being actively exploited?

No, this vulnerability is not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog and no public exploits are available, though the critical CVSS 10.0 score makes it a high-priority remediation target.

What versions of Docker are affected by CVE-2026-44181?

Jupyter Enterprise Gateway versions 2.1.0 through 3.2.x are vulnerable. The vulnerability was fixed in version 3.3.0. This affects Docker deployments running the affected Enterprise Gateway versions on Kubernetes, Apache Spark, or Docker Swarm clusters.

How do I check if my server is vulnerable to CVE-2026-44181?

Run 'docker images | grep jupyter' to list Jupyter-based containers, then use 'docker inspect {image_id}' to check the version label, or execute 'docker run --rm {image} jupyter enterprisegateway --version' to determine if the version falls within 2.1.0-3.2.x range.

Does Defensia detect CVE-2026-44181?

Yes — Defensia's CVE advisory scanner compares installed package versions against the NVD database. If Docker or Jupyter Enterprise Gateway is installed on a monitored server, CVE-2026-44181 will appear in your dashboard with remediation steps.

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References

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