CVE-2026-71869

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 array item 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.

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 array item 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.

Summary

Orval's zod schema generation emits the array-items 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

export const …Default = `v${globalThis.ORVPWN()}w`;   // ${...} = arbitrary JS expression, runs at import

Malicious input: an array property (string items) 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 (+ make_spec.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. maintainer-report.txt make_spec.pyreproduce.sh

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 array item 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.

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 array item 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.

Summary

Orval's zod schema generation emits the array-items 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

export const …Default = `v${globalThis.ORVPWN()}w`;   // ${...} = arbitrary JS expression, runs at import

Malicious input: an array property (string items) 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 (+ make_spec.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. maintainer-report.txt make_spec.pyreproduce.sh

Root has patched CVE-2026-71869 in the orval package for Root:npm. Multiple fixed versions available.