AIKIDO-2026-889206

TL;DR

The local object storage emulator builds on-disk paths by joining untrusted bucket and object names from request paths directly onto its storage directory. Because .. segments, including percent-encoded forms that decode after routing, are not rejected, a request to the local bucket server can escape the storage directory and read, overwrite, or delete arbitrary files with the privileges of the Encore daemon. Exposure is limited to local development and requires knowing the randomly generated namespace id used to route bucket requests. The fix validates both path components with a local-path check and returns an error for any name that escapes the directory.