GHSA-88f2-fpv8-89q2 Orval: RCE via servers[].url -> unescaped request-URL template literal (with getBaseUrlFromSpecification)

• npm orval: < 8.21.0 → fixed in 8.21.0

Summary When Orval is configured with `output.baseUrl.getBaseUrlFromSpecification: true`, it bakes the spec's `servers[0].url` into the generated request URL as a template literal without escaping the backtick. A server URL containing a backtick closes the template literal and injects a concatenation expression evaluated when the generated URL/request function is called, executing attacker-controlled code. Verified on Orval 8.19.0 (fetch client); survives default OpenAPI validation. Details ```ts return `http://api.x/` + (globalThis.X = require("fs").writeFileSync("/marker","pwned")) + `/v1/u`; ``` Prerequisite: the documented `getBaseUrlFromSpecification: true` option (takes the base URL from the OpenAPI servers block). This is the same output sink as the route-path case (request-URL template literal) reached via the server `url` field. Distinct from Orval's published CVEs (CVE-2026-22785 summary/MCP, CVE-2026-23947 / CVE-2026-25141 x-enumDescriptions, CVE-2026-24132 const/mock). PoC `reproduce.sh` (+ `make_spec.py`) attached: generates a fetch client with `getBaseUrlFromSpecification: true`, bundles it, calls the functions, and shows a marker written. Verified on 8.19.0. Impact With that option enabled, code execution in any environment that calls a client generated from an attacker-controlled or attacker-influenced OpenAPI description. Suggested fix Escape the server URL before emitting it into the URL template literal (escape backtick and `${`), or build the base URL with an encoder that treats it as data; validate the URL. maintainer-report.txt make_spec.py reproduce.sh