CVE-2026-71871

### Summary Orval's zod schema generation emits the **header-parameter** `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`; // ${...} = arbitrary JS expression, runs at import ``` Malicious input: a header parameter with a `default` of `v${<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. [make_spec.py](https://github.com/user-attachments/files/29399137/make_spec.py) [reproduce.sh](https://github.com/user-attachments/files/29399138/reproduce.sh)