RUSTSEC-2026-0138 Unsound access to padding bytes while serializing date/time values using the Mysql backend
Unsound memory access in diesel-async allows attackers to potentially execute code or read sensitive data via crafted date/time inputs.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is RUSTSEC-2026-0138?
RUSTSEC-2026-0138 is a memory corruption vulnerability in diesel-async, published on 30 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Diesel-async uses the mysql-async crate for interacting with Mysql compatible databases. This library already provides access to deserialized data for date/time releated types. Diesel-async then translated these deserialized data back to their serialized binary representation to hook into diesels desearialization framework.
While serializing these data/time values again Diesel-async relied on a cast between the MysqlTime #[repr(C)] struct (defined by Diesel) and a byte array. As this cast exposes padding bytes contained in this struct, this is undefined behaviour.
This vulnerability affects any user deserializing date/time values using the Mysql backend and diesel-async.
This affects any usage of the following functions with a AsyncMysqlConnection provided by diesel-async:
diesel::serialize::FromSql<Timestamp, Mysql>diesel::serialize::FromSql<Time, Mysql>diesel::serialize::FromSql<Date, Mysql>diesel::serialize::FromSql<DateTime, Mysql>
Mitigation
The preferred mitigation to the outlined problem is to update to Diesel-async version 0.9.0 or newer, which includes fixes for the problem.
Resolution
Diesel-async now just calls a safe serialization method provided by Diesel 2.3.9 and newer
Which versions are affected by RUSTSEC-2026-0138?
1 open source package ship an affected version, including diesel-async.
| Package | Affected | Fixed in |
|---|---|---|
diesel-async crates.io | From 0.0.0-0 | 0.9.0 |
How do I fix RUSTSEC-2026-0138?
Upgrade diesel-async to 0.9.0 or later.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is RUSTSEC-2026-0138 being exploited?
There is no known exploitation of RUSTSEC-2026-0138 in the wild and no public exploit code.