GHSA-q342-9w2p-57fp

### Impact

The `requestKeywordDenylist` security control can be bypassed by placing any nested object or array before a prohibited keyword in the request payload. This is caused by a logic bug that stops scanning sibling keys after encountering the first nested value. Any custom `requestKeywordDenylist` entries configured by the developer are equally by-passable using the same technique.

All Parse Server deployments are affected. The `requestKeywordDenylist` is enabled by default.

### Patches

The fix replaces the recursive object scanner with an iterative stack-based traversal that processes all nested values without prematurely exiting the scan loop. This also eliminates a potential stack overflow on deeply nested payloads.

### Workarounds

Use a Cloud Code `beforeSave` trigger to validate incoming data for prohibited keywords across all classes.

### References

- GitHub security advisory: https://github.com/parse-community/parse-server/security/advisories/GHSA-q342-9w2p-57fp - Fix Parse Server 9: https://github.com/parse-community/parse-server/releases/tag/9.5.1-alpha.1 - Fix Parse Server 8: https://github.com/parse-community/parse-server/releases/tag/8.6.12