CVE-2026-71868: Orval: Import-time RCE via enum-typed default -> zod module-level template literal
Summary
Orval's zod schema generation emits the enum-typed 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 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 …Default = v${globalThis.ORVPWN()}w; // ${...} = arbitrary JS expression, runs at import
Malicious input: an enum-typed property with a default of v${<attacker JS>}w. ${...} permits any JS expression.
Note: this is one of several default-bearing positions that reach the same unescaped zod template-literal sink; a single fix (escape default values) closes all of them, and a CNA may choose to consolidate the related reports.
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. Apply to every default position.
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 an enum 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
Which environments can be affected by this issue?
Any environment that imports a generated Zod schema module can execute the injected code, including developer workstations, CI systems, test environments, and applications. Exposure requires generating and importing schemas from an attacker-controlled or otherwise untrusted OpenAPI v3 or Swagger v2 specification.
What must an attacker control to trigger code execution?
The attacker needs to supply an enum default value containing a ${...} expression or a backtick in the API specification. When Orval generates the Zod schema and the resulting module is imported, the injected JavaScript can be evaluated.
What version resolves the issue?
Upgrade Orval to version 8.21.0 or later. Versions prior to 8.21.0 are affected in the Zod schema generation path.