Orval: Import-time RCE via header-parameter default -> zod module-level template literal

### 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) Source Code Location: https://github.com/orval-labs/orval Affected Packages: - npm:orval, affected < 8.21.0, patched in 8.21.0 CWEs: - CWE-94: Improper Control of Generation of Code ('Code Injection') - CWE-116: Improper Encoding or Escaping of Output - CWE-1336: Improper Neutralization of Special Elements Used in a Template Engine CVSS: - CVSS_V4: score 9.3, CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N References: - https://github.com/orval-labs/orval/security/advisories/GHSA-8j6p-r8jg-mxqh - https://nvd.nist.gov/vuln/detail/CVE-2026-71871 - https://github.com/orval-labs/orval/pull/3692 - https://github.com/orval-labs/orval/commit/8ef1bfdf3f9bcaf9dabfbe2e42887f1c0e159ab6 - https://github.com/orval-labs/orval/releases/tag/v8.21.0 - https://github.com/advisories/GHSA-8j6p-r8jg-mxqh