CVE-2026-72717: Orval: Import-time RCE via schema default -> zod module-level template literal
Summary
Orval's zod schema generation emits a schema's default value as a module-level template literal (export const …Default = <default>;) without escaping ${ or the backtick. A default of the form v${<code>}w injects a live JavaScript expression that is evaluated when the generated zod schema module is imported, executing attacker-controlled code at import — no request or function call needed. Verified on Orval 8.19.0; survives default OpenAPI validation.
Details
ts export const getIResponseDsDefault = v${globalThis.ORVPWN()}w;
${...} permits an arbitrary JS expression. Orval escapes its other value sinks (enum, mock, regex, object-default values) with \' inside single-quoted strings; the string default is the one value emitted as a backtick template literal, so ${...}/backtick are interpreted, not escaped. Distinct from the URL-template-literal cases (different field and sink) and from the published Orval CVEs (summary/MCP, x-enumDescriptions, const/mock).
PoC
reproduce.sh (+ makespec.py) attached: generates the zod schema with default validation, bundles it, imports it, and shows a marker written at import. Verified on 8.19.0.
Impact
Code execution at import in any application that imports a zod schema module generated from an attacker-controlled or attacker-influenced OpenAPI description.
Suggested fix
Emit default values via a proper string-literal encoder (JSON.stringify, or escape backtick and ${ if a template literal must be used); never interpolate a spec value into a template literal.
maintainer-report.txt makespec.py reproduce.sh
Other sources
Orval generates type-safe JavaScript clients in TypeScript from OpenAPI v3 and Swagger v2 specifications. Prior to 8.21.0, a ${...} expression or backtick in a schema default is emitted into a module-level template literal emitted by zod schema generation without safe encoding. This permits attacker-controlled JavaScript to be evaluated when the generated zod schema module is imported, resulting in code execution in the developer, CI, test, or application environment. The affected code is packages/zod/src/index.ts function formatDefaultValue. This issue is fixed in version 8.21.0.
— MITRE
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
npm/orvalto a version that resolves this vulnerability.Fixed in 8.21.0 - Upgrade
Upgrade
Orvalto a version that resolves this vulnerability.Fixed in 8.21.0
Event History
Frequently Asked Questions
Who is exposed to this issue?
Users of npm/orval versions prior to 8.21.0 are exposed when they generate Zod schemas from an OpenAPI or Swagger specification containing attacker-controlled schema default values and later import the generated schema module. The code can run in developer workstations, CI, test, or application environments.
What must an attacker control to exploit it?
An attacker needs to supply or influence a schema default value in an OpenAPI v3 or Swagger v2 specification. A ${...} expression or backtick in that default can be emitted unsafely into a module-level template literal during Zod schema generation.
When does the injected code execute?
The attacker-controlled JavaScript is evaluated when the generated Zod schema module is imported. Generation alone is not described as the execution point; importing the generated module triggers the risk.
What version fixes the issue?
Upgrade Orval to version 8.21.0, which fixes the unsafe handling in the Zod schema default-value generation path.