CVE-2026-44181 Jupyter Enterprise Gateway: Jinja2 Template Server Side Template Injection results in Remote Code Execution
Attackers can execute arbitrary code via Jinja2 template injection in Kubernetes manifests, potentially compromising the cluster.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-44181?
CVE-2026-44181 is a critical code injection vulnerability in jupyter-server enterprise_gateway, published on 16 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
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.
Weakness: CWE-1336
Which versions are affected by CVE-2026-44181?
3 open source packages ship an affected version, including jupyter_enterprise_gateway and jupyter-enterprise-gateway. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
jupyter_enterprise_gateway PyPI | From 2.0.0rc2 | 3.3.0 |
jupyter-enterprise-gateway PyPI | From 2.0.0rc2 | 3.3.0 |
jupyter-enterprise-gateway PyPI | From 2.0.0rc2 | 3.3.0 |
Products include Jupyter Enterprise Gateway.
How do I fix CVE-2026-44181?
Upgrade jupyter_enterprise_gateway to 3.3.0 or later.
Upgrade, and never evaluate templates, expressions or code built from user input. More about Code injection.
Is CVE-2026-44181 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-44181 exists.
Other vulnerabilities in jupyter-server enterprise_gateway
Sources
Also known as GHSA-f49j-v924-fx9w, PYSEC-2026-364.