Diesel allows to register custom aggregate SQL functions for SQLite via the SqliteAggregate interface.
To store an instance of the custom aggregate processor Diesel relied on the sqlite3_aggregate_context function provided by sqlite. This function doesn't provide any guarantees about alignment of the returned allocation, which in turn can lead to problems if the type implementing requires a special alignment, e.g. via a custom #[align(x)] attribute on the type implementing this trait. This affects any user of SqliteAggregate that registers the custom aggregate function with an SQLite connection, while using a non-standard alignment on the type implementing this trait.
The preferred mitigation to the outlined problem is to update to a Diesel version 2.3.8 or newer, which includes fixes for the problem.
Diesel now allocates the corresponding memory on Rust side to get a correctly aligned allocation.
{
"cwe_ids": [
"CWE-188"
],
"github_reviewed": true,
"github_reviewed_at": "2026-05-19T19:39:37Z",
"nvd_published_at": null,
"severity": "MODERATE"
}