The Matrix Rust SDK is a collection of libraries that make it easier to build Matrix clients in Rust. An SQL injection vulnerability in the EventCache::find_event_with_relations method of matrix-sdk 0.11 and 0.12 allows malicious room members to execute arbitrary SQL commands in Matrix clients that directly pass relation types provided by those room members into this method, when used with the default sqlite-based store backend. Exploitation is unlikely, as no known clients currently use the API in this manner. This vulnerability is fixed in 0.13.