Reported

April 24, 2026

Issued

May 13, 2026

Package

diesel (crates.io)

Type

Vulnerability

References

• https://github.com/diesel-rs/diesel/pull/5042

Patched

• >=2.3.8

Affected Functions

Version

diesel::sqlite::SqliteAggregate

• <2.3.8

Description

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.

Mitigation

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.

Resolution

Diesel now allocates the corresponding memory on Rust side to get a correctly aligned allocation.

Advisory available under CC0-1.0 license.