CVE-2026-71871: Orval: Import-time RCE via header-parameter default -> zod module-level template literal
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 header parameter 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.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- 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 Orval versions before 8.21.0 are exposed when they generate Zod schemas from an OpenAPI v3 or Swagger v2 specification containing a crafted header parameter default. The generated schema can execute code when it is imported in a developer, CI, test, or application environment.
What does an attacker need to exploit it?
An attacker needs control over, or the ability to influence, an API specification processed by Orval. The specification must include a header parameter default containing a ${...} expression or a backtick so that unsafe JavaScript is emitted into the generated module-level template literal.
How can I mitigate the issue if I cannot upgrade immediately?
Do not generate or import Zod schema output from untrusted or insufficiently reviewed OpenAPI or Swagger specifications. Review header parameter default values for backticks and ${...} expressions before running Orval generation or importing generated modules.
How can I determine whether generated output may already be affected?
Inspect generated Zod schema modules produced by versions before 8.21.0, especially output derived from header parameters with default values. Look for attacker-controlled content embedded in module-level template literals, including backticks or ${...} expressions.