Security Digest · Vulnerability record
CVE-2026-44182: Jupyter Enterprise Gateway: Kubernetes Manifest Injection in Jinja2 Template Rendering
Jupyter Enterprise Gateway launches remote Jupyter Notebook kernels across distributed clusters like Apache Spark, Kubernetes, and Docker Swarm.
CVSS 10.0 Critical EPSS 0.6% · p50
Should you act?
Critical and remotely reachable
No known exploitation yet, but it is network-reachable without credentials. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.
- Not in CISA KEV, but CISA’s SSVC assessment records a public proof-of-concept, so attack code exists.
- EPSS 0.6%, percentile 50: FIRST’s model estimates a 0.6% chance of exploitation activity in the next 30 days, higher than 50% of all scored CVEs (low). EPSS is a probability, not a verdict.
- Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
- Only applies if your dependency tree includes
jupyter_enterprise_gateway(PyPI) < 3.3.0, fixed in 3.3.0. Check your lockfile, including transitive dependencies.
What it is
Jupyter Enterprise Gateway launches remote Jupyter Notebook kernels across distributed clusters like Apache Spark, Kubernetes, and Docker Swarm. In versions prior to 3.3.0, the server interpolates untrusted environment variables (e.g., KERNELXXX) into Kubernetes manifests without YAML-aware escaping, enabling YAML injection attacks. Attackers can inject new fields, overwrite critical fields (e.g., duplicate securityContext keys, where the last one prevails), and inject document boundaries (--- for new documents, ... for end-of-document) to generate multiple resources, potentially creating arbitrary types, such as privileged pods. The Jinja2 template for the Kubernetes manifest contains several kernelxxx variables, such as kernelworkingdir that are used when rendering the manifest and are all vectors for YAML injection. This issue has been fixed in version 3.3.0.
From the GitHub advisory
Summary
The environment variables used during the rendering of the Kubernetes manifest allow YAML injection, enabling attackers to overwrite existing keys like securityContext and inject multi-document YAML to create additional unintended Kubernetes resources.
Details
The server interpolates untrusted environment variables (e.g., KERNELXXX) into Kubernetes manifests without YAML-aware escaping, enabling YAML injection attacks. Attackers can inject new fields, overwrite critical fields (e.g., duplicate securityContext keys, where the last one prevails), and inject document boundaries (--- for new documents, ... for end-of-document) to generate multiple resources, potentially creating arbitrary kinds like privileged pods.
The Jinja2 template for the Kubernetes manifest contains several kernelxxx variables, such as kernelworkingdir that are used when rendering the manifest and are all vectors for YAML injection. https://github.com/jupyter-server/enterprisegateway/blob/152c20f162f2fab700c04c8830ebf8c1e2e2217a/etc/kernel-launchers/kubernetes/scripts/kernel-pod.yaml.j2#L77
Weakness type: CWE-74.
Product: jupyter_enterprise_gateway (PyPI) · Assigned by: GitHub_M · Published: 2026-07-16
Affected and fixed versions
| Ecosystem | Package | Vulnerable | First fixed |
|---|---|---|---|
| PyPI | jupyter_enterprise_gateway | < 3.3.0 | 3.3.0 |
| Vendor | Product | Affected versions (per CVE record) |
|---|---|---|
| jupyter-server | enterprise_gateway | < 3.3.0 |
Severity scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_M | 4.0 | 10 Critical | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H |
| GitHub | 4.0 | 10.0 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H |
- Attack vector: network (remotely reachable)
- Attack complexity: low
- Attack requirements: none
- Privileges required: none (no login)
- User interaction: none
CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.
Exploitation and urgency
- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation poc, automatable yes, technical impact total.
- FIRST EPSS (model of 2026-10-21): 0.63% probability of exploitation activity in the next 30 days; percentile 50.
Timeline
- — GitHub-reviewed advisory GHSA-cfw7-6c5v-2wjq published (critical)
- — CVE record published by GitHub_M
- — CVE record last updated
Sources and references
Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.
Vulnerability records
- GitHub Advisory GHSA-cfw7-6c5v-2wjq github.com
- CVE.org record CVE-2026-44182 cve.org
- NVD entry CVE-2026-44182 nvd.nist.gov
Other references from the CVE record and advisory
- github.com github.com
- github.com github.com