External risk intelligence

Amazon Virtual Engineering Workbench Publishing Component Code Execution Vulnerability

CVE advisorySeverity: CRITICAL (CVSS 9.4)

CVE-2026-119085

The vulnerability exists in a publishing component API of the Amazon Virtual Engineering Workbench, which is a specialized internal engineering tool. While it is network-reachable via an API, such developer-focused workbench environments are typically deployed within private, authenticated, or restricted corporate network segments rather than being exposed directly to the public internet.

Halo Surface Signal: 3 out of 5 — possibly public-facing.

External exposure likelihood

Horizon Alert

Summary of the vulnerability and why it matters

A vulnerability in the Amazon Virtual Engineering Workbench's publishing component could allow authenticated users to execute arbitrary code. This could potentially grant access to sensitive data and resources across tenant projects by exploiting a flaw in how special elements within a template engine are handled. The issue is reachable through a specially crafted CloudFormation template submitted via the product versioning API.

Issue: Unauthorized code execution via template input.
Why remember: Affects access to tenant project data.
Executive takeaway: Confirm relevance and exposure.

Attack Path

How an attacker could exploit the issue

An attacker with existing access could exploit this vulnerability by submitting a specially crafted CloudFormation template. This template, containing malicious directives, would be processed by the publishing component's template engine. Successful exploitation could allow the attacker to execute arbitrary code with elevated privileges, potentially accessing sensitive data across tenant projects.

Requires authenticated user access.
Triggered by submitting a malicious template.
Risk of arbitrary code execution and data access.

Live Threat

Current exploitation, exposure, and threat context

When supported by the advisory, a remote authenticated third party could run arbitrary code with the permissions of the publishing Lambda's IAM role. This could potentially allow access to data and resources across all tenant projects within the Amazon Virtual Engineering Workbench publishing component.

Tenant project data and resources.
Via crafted CloudFormation template submitted through API.
Arbitrary code execution with IAM role permissions.

Operational Fix

Recommended remediation, mitigation, and detection steps

Security and platform teams managing Amazon Virtual Engineering Workbench (VEW) deployments should prioritize this vulnerability. The immediate first step is to identify all VEW instances, confirm their accessibility and criticality, and locate the accountable owner for each. Remediation planning should then be risk-based, potentially involving vendor coordination for the fix.

Platform or application owners should own this.
Verify VEW instance reachability and criticality.
Redeploy from the latest VEW version.

Supplementary metadata

CVSS vector

Validate whether this threat affects your internet-facing exposure.

Halo Threat Intelligence helps prioritize remediation with Halo Surface Signal and H/A/L/O context. Start exposure validation with a free external attack surface trial.

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Frequently asked questions

What is Amazon Virtual Engineering Workbench?

Amazon Virtual Engineering Workbench (VEW) is an open-source tool provided by AWS labs designed to support engineering teams. It functions as a development environment that handles infrastructure-as-code tasks, such as managing and publishing CloudFormation templates. It acts as an orchestration layer, helping developers streamline deployment workflows within their cloud environments.

What does CWE-1336 mean for CVE-2026-119085?

This vulnerability involves Improper Neutralization of Special Elements Used in a Template Engine. Essentially, the software fails to properly filter out malicious instructions hidden within template data. Because it treats these user-supplied inputs as executable commands rather than plain text, a threat actor can force the system to perform unintended actions.

How is the vulnerability triggered?

The flaw is triggered when a user submits a specially crafted CloudFormation template to the product versioning API. The publishing component processes this input through its template engine, where malicious directives are executed. It is important to note that this requires valid authentication; an anonymous user cannot trigger the bug simply by reaching the API.

Is my instance at risk according to Halo Surface Signal?

Halo Surface Signal identifies this as a network-reachable issue, but it is typically contained within restricted or private engineering segments. While it is classified as external due to the network vector, it is rarely exposed directly to the public internet. You should focus on instances accessible to internal users who might have malicious intent or compromised credentials.

How do I respond to this threat?

Begin by identifying all active VEW deployments within your infrastructure and determining who owns each instance. Once you have an inventory, prepare to update your environment by redeploying the software from the latest official version provided by the awslabs repository. This redeployment is the primary method to apply the necessary security fixes for this template engine flaw.

References

Written by Nicholas Merritt

Nicholas Merritt is VP of Security Solutions at Halo Security. With more than 25 years across application security, vulnerability prioritization, and offensive security, he helps teams translate threat data into practical exposure validation and remediation focus. He authors Halo Threat Intelligence CVE advisories using Halo Surface Signal and H/A/L/O context to prioritize internet-facing risk.