GHSA-gqh3-7856-rjjg - ApostropheCMS: :_id/locales REST route omits the public-API authorization gate its sibling read routes enforce (unauthenticated doc-existence + locale metadata disclosure)

## Summary The REST route `GET /api/v1/<piece-type>/:_id/locales` (and the equivalent page route) does not apply the `publicApiCheckAsync` gate that ApostropheCMS's other read routes enforce. An unauthenticated caller can therefore query this route for any document `_id` and learn whether the document exists and which locales it is published in — a document-existence and locale-metadata disclosure that the read-API is otherwise supposed to gate. ## Affected - Repository: `apostrophecms/apostrophe` (monorepo package `apostrophe`). - Confirmed at **4.32.2** (commit `d3ff8c9` == the shipped 4.32.2; unchanged at current HEAD). No fix at time of report. - Stack: Node.js / Express + MongoDB. - Endpoints: `GET /api/v1/<piece-type>/:_id/locales` and `GET /api/v1/@apostrophecms/page/:_id/locales`. ## Technical detail - Unsafe: `modules/@apostrophecms/piece-type/index.js:397` registers the `:_id/locales` route with **no** `publicApiCheckAsync`. The page module has the same omission at `modules/@apostrophecms/page/index.js:925`. - Gated siblings: the read routes in the same module (e.g. `getAll` at `piece-type/index.js:256-263`) call `publicApiCheckAsync` (`:263`) to enforce the public-API access policy. - So the `locales` handler (which calls `getLocales()` for the document) runs for any caller regardless of the public-API gate the other read routes apply, returning the document's locale/publication metadata without authorization. ## Impact An unauthenticated caller can confirm the existence of a document by `_id` and enumerate its locales/publication state — information the read-API is meant to gate. Defensibly 4.3 (AC:H) given the opaque `_id` precondition (the caller needs a document id). ## How it was verified (local only) Reproduced against `apostrophe@4.32.2` (== commit `d3ff8c9`) locally with synthetic content: - Source review confirmed the `:_id/locales` route lacks `publicApiCheckAsync` while the sibling read routes have it. - An **unauthenticated** `GET /api/