# RUSTSEC-2026-0134: Unsound access to padding bytes while serializing date/time values using the Mysql backend

> Unsound memory access in Diesel's MySQL backend allows reading padding bytes, potentially leaking sensitive data during date/time serialization.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 24 Apr 2026

## What is RUSTSEC-2026-0134?

RUSTSEC-2026-0134 is a memory corruption vulnerability in diesel, published on 24 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Diesel relies on libmysqlclient for interacting with Mysql compatible databases. This library requires to provide date/time values according to the byte layout of their `MYSQL_TIME` type.

Diesel replicated this type as `#[repr(C)]` struct, populated all the fields of this struct and then casted this value to an array of bytes. As this cast exposes padding bytes contained in this struct, this is undefined behaviour.

This vulnerability affects any user serializing date/time values using the Mysql backend.

## Mitigation

The preferred mitigation to the outlined problem is to update to Diesel version 2.3.8 or newer, which includes fixes for the problem.

## Resolution

Diesel now manually serializes the relevant data without accessing the padding bytes.

## Which versions are affected by RUSTSEC-2026-0134?

1 open source package ship an affected version, including diesel.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `diesel` | crates.io | From 0.0.0-0 | 2.3.8 |

## How do I fix RUSTSEC-2026-0134?

Upgrade diesel to 2.3.8 or later.

## Is RUSTSEC-2026-0134 being exploited?

There is no known exploitation of RUSTSEC-2026-0134 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for RUSTSEC-2026-0134 and fix it if it is affected.

What it is: RUSTSEC-2026-0134 is a memory corruption vulnerability in diesel, published on 24 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of RUSTSEC-2026-0134 in the wild and no public exploit code.

Affected packages and fixed versions:
- diesel (crates.io): affected from 0.0.0-0; fixed in 2.3.8

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/RUSTSEC-2026-0134/ (Markdown: https://insights.sbomify.com/RUSTSEC-2026-0134/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/RUSTSEC-2026-0134

---
From sbomify Insights: https://insights.sbomify.com/RUSTSEC-2026-0134/
Summaries are generated and may contain mistakes; the official description above is the record.