CVE-2026-59148: @Mockoon/commons-server: Unauthenticated admin API + wildcard CORS allows mock-state hijack and secret theft
Mockoon’s admin API (commons-server/src/libs/server/admin-api.ts) is mounted on the same Express listener as the user-defined mock routes, enabled by default in every shipped runtime (commons-server, CLI, serverless), serves Access-Control-Allow-Origin: * on every endpoint with all HTTP methods allowed including PUT/POST/PATCH/DELETE/PURGE and Content-Type in Access-Control-Allow-Headers, and has zero authentication of any kind (no token, no shared secret, no MOCKOON_ADMIN_TOKEN env var — searched the repo, returns zero hits).
Any unauthenticated caller who can reach the mock server’s port (default 0.0.0.0:3000) can:
- Read every
MOCKOON_*env var used by the operator as secret material in templates (getEnvVarhelper). - Write arbitrary process env vars (no prefix check on the WRITE path) — poison operator’s
MOCKOON_API_KEY,MOCKOON_JWT_SECRET, …, or write process-level vars likeAWS_SECRET_ACCESS_KEYthat the surrounding runtime consumes. - Rewrite every mock route’s body / status / headers in-runtime via
PUT /mockoon-admin/environment— downstream consumers (frontend dev-server, CI test suite, integration partner) receive attacker-controlled responses and headers includingSet-Cookie,Location,Content-Security-Policy, etc. - Read transaction logs / SSE stream (consumer’s request bodies + auth headers in clear).
- Read/write global template vars; purge state / data buckets / logs.
Because of the wildcard CORS reply, the attack also lands cross-origin from a browser: a developer who runs mockoon-cli start ... locally and visits a malicious website gets their mock state hijacked.
References
- github.com/advisories/GHSA-rqx4-3f6q-3x2v
- github.com/mockoon/mockoon/commit/c420b5a56918475b8663977b51e5f986e45b3299
- github.com/mockoon/mockoon/pull/2254
- github.com/mockoon/mockoon/releases/tag/v9.7.0
- github.com/mockoon/mockoon/security/advisories/GHSA-rqx4-3f6q-3x2v
- mockoon.com/releases/9.7.0
- nvd.nist.gov/vuln/detail/CVE-2026-59148
Code Behaviors & Features
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