A SQL injection vulnerability in "FilterEngine.create_sqla_query()" allows any authenticated Rucio user to execute arbitrary SQL against the backend database through the DID search endpoint ("GET /dids/<scope>/dids/search"). On Oracle deployments attacker-controlled filter keys and values are interpolated directly into "sqlalchemy.text()" via Python ".format()", completely bypassing parameterization. This enables full database compromise including extraction of authentication tokens, password hashes, and all managed data identifiers. This affects versions 1.27.0 and later before 35.8.5, 38.5.5, 39.4.2, and 40.1.1. The vulnerability exists in "lib/rucio/core/did_meta_plugins/filter_engine.py" within the "create_sqla_query()" method. When the database dialect is Oracle, filter expressions for JSON metadata columns are constructed using "text()" with Python string formatting. Both "key" and "value" are attacker-controlled strings derived from HTTP query parameters. The "text()" function creates a raw SQL fragment — it does not escape or parameterize its contents. Any authenticated Rucio user can exploit this through the DID search API to execute arbitrary SQL against the backend database. This can expose all managed data identifiers and sensitive tables such as identities, tokens, accounts, rse_settings, and rules, and may allow modification of database contents. The issue affects Oracle deployments using the default json_meta plugin and does not affect PostgreSQL or MySQL deployments using that plugin. This vulnerability has been fixed in versions 35.8.5, 38.5.5, 39.4.2, and 40.1.1.