CVE-2026-62681

Orval generates type-safe JavaScript clients in TypeScript from OpenAPI v3 and Swagger v2 specifications. Prior to 8.21.0, an unescaped backtick in an OpenAPI path is emitted into request URL template literals generated for axios, fetch, react-query, and SWR clients without safe encoding. This permits attacker-controlled JavaScript to be evaluated when a generated request, URL-builder, or query-key function is called, resulting in code execution in the developer, CI, test, or application environment. The affected code is packages/core/src/getters/route.ts and route generation consumers. 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, an unescaped backtick in an OpenAPI path is emitted into request URL template literals generated for axios, fetch, react-query, and SWR clients without safe encoding. This permits attacker-controlled JavaScript to be evaluated when a generated request, URL-builder, or query-key function is called, resulting in code execution in the developer, CI, test, or application environment. The affected code is packages/core/src/getters/route.ts and route generation consumers. This issue is fixed in version 8.21.0.

Summary

Orval emits the OpenAPI path into the generated request URL as a TEMPLATE LITERAL (`/users/...`) without escaping the backtick character. A path containing a backtick closes the template literal and injects a concatenation expression that is evaluated when the generated URL/request/key function is called, executing attacker-controlled code. Affects the axios, fetch, react-query, and swr clients. Verified on Orval 8.19.0; survives Orval's default OpenAPI validation.

Details

// generated URL builder (fetch client)
return `/users/` + (globalThis.X = require("fs").writeFileSync("/marker","pwned")) + `/list`;

The backtick in the path terminates the `...` literal; + (<code>) + runs as a live expression; a trailing backtick reopens a template literal so the file stays valid. The code runs whenever the generated request function, URL builder, or query-key function is called.

This is distinct from Orval's four published CVEs: CVE-2026-22785 (summary -> MCP server), CVE-2026-23947 / CVE-2026-25141 (x-enumDescriptions), and CVE-2026-24132 (const -> mock files). This is a different field (the route path) and a different sink (the request-URL template literal), which those advisories and their fixes do not cover.

PoC

reproduce.sh (+ make_spec.py) attached: generates a fetch client with default validation, bundles it, calls the generated functions, and shows a marker file written. Verified on 8.19.0.

Impact

Code execution in any environment that calls a client generated from an attacker-controlled or attacker-influenced OpenAPI description (developer, CI, or the running application).

Suggested fix

Escape the path before emitting it into the URL template literal (escape backtick and ${, or build the URL with an encoder that treats the path as data), and validate path characters.

Orval generates type-safe JavaScript clients in TypeScript from OpenAPI v3 and Swagger v2 specifications. Prior to 8.21.0, an unescaped backtick in an OpenAPI path is emitted into request URL template literals generated for axios, fetch, react-query, and SWR clients without safe encoding. This permits attacker-controlled JavaScript to be evaluated when a generated request, URL-builder, or query-key function is called, resulting in code execution in the developer, CI, test, or application environment. The affected code is packages/core/src/getters/route.ts and route generation consumers. 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, an unescaped backtick in an OpenAPI path is emitted into request URL template literals generated for axios, fetch, react-query, and SWR clients without safe encoding. This permits attacker-controlled JavaScript to be evaluated when a generated request, URL-builder, or query-key function is called, resulting in code execution in the developer, CI, test, or application environment. The affected code is packages/core/src/getters/route.ts and route generation consumers. This issue is fixed in version 8.21.0.

Summary

Orval emits the OpenAPI path into the generated request URL as a TEMPLATE LITERAL (`/users/...`) without escaping the backtick character. A path containing a backtick closes the template literal and injects a concatenation expression that is evaluated when the generated URL/request/key function is called, executing attacker-controlled code. Affects the axios, fetch, react-query, and swr clients. Verified on Orval 8.19.0; survives Orval's default OpenAPI validation.

Details

// generated URL builder (fetch client)
return `/users/` + (globalThis.X = require("fs").writeFileSync("/marker","pwned")) + `/list`;

The backtick in the path terminates the `...` literal; + (<code>) + runs as a live expression; a trailing backtick reopens a template literal so the file stays valid. The code runs whenever the generated request function, URL builder, or query-key function is called.

This is distinct from Orval's four published CVEs: CVE-2026-22785 (summary -> MCP server), CVE-2026-23947 / CVE-2026-25141 (x-enumDescriptions), and CVE-2026-24132 (const -> mock files). This is a different field (the route path) and a different sink (the request-URL template literal), which those advisories and their fixes do not cover.

PoC

reproduce.sh (+ make_spec.py) attached: generates a fetch client with default validation, bundles it, calls the generated functions, and shows a marker file written. Verified on 8.19.0.

Impact

Code execution in any environment that calls a client generated from an attacker-controlled or attacker-influenced OpenAPI description (developer, CI, or the running application).

Suggested fix

Escape the path before emitting it into the URL template literal (escape backtick and ${, or build the URL with an encoder that treats the path as data), and validate path characters.

Root has patched CVE-2026-62681 in the orval package for Root:npm. Multiple fixed versions available.