Unsound HighRUSTSEC-2026-0111 · diesel
RUSTSEC-2026-0111: Possible UTF-8 corruption in Diesels SQLite backend
Short answerdiesel has an API that can cause undefined behaviour from safe code: Possible UTF-8 corruption in Diesels SQLite backend. Fixed in 2.3.8.
| Crate | diesel |
|---|---|
| Type | Unsound |
| Affected versions | Before 2.3.8. |
| Fixed in | 2.3.8 |
| Severity | High (GitHub rating) |
| Published | 2026-04-24 |
| Last changed | 2026-05-06 |
| Also known as | GHSA-h5x4-m2qf-r4f2 |
| Affected functions | diesel::deserialize::FromSql::<Text,Sqlite>::from_sql, diesel::sqlite::SqliteValue::read_str |
What to do
- See which version you have:
cargo tree -i diesel(it also shows which of your dependencies pulls it in). - Update within your version requirement:
cargo update -p diesel. If the fix is a newer major or minor than your requirement allows, raise it in Cargo.toml (for examplediesel = "2.3.8") or update the dependency that pulls it in. - Check again with
cargo audit, or paste your Cargo.lock into our Cargo.toml checker.
Details from the advisory
Diesel uses the sqlite3_value_text function to receive strings from SQLite while deserializing query results. We misinterpreted the corresponding SQLite documentation that this function always returns a UTF-8 encoded string values as *const c_char. Based on that we used str::from_utf8_unchecked to construct a Rust string slice without any additional UTF-8 checks in place. It turned out that this function doesn't always return correct UTF-8 strings. For field of the SQLite side storage type BLOB this pointer can contain arbitrary bytes, which makes the usage of str::from_utf8_unchecked unsound as this violates the safety contract of str to only contain valid UTF-8 encoded Strings.
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 correctly checks whether the provides byte buffer is actually valid UTF-8, instead of relying on SQLite's documentation. This fix is included in the 2.3.8 release.
References
- Package: crates.io/crates/diesel
- Advisory: rustsec.org/advisories/RUSTSEC-2026-0111.html
- Web: github.com/diesel-rs/diesel/pull/5042
From the RustSec Advisory Database (CC0-1.0) via the OSV export, downloaded Oct 24, 2026. Severity score computed from the published CVSS vector.
Other advisories for diesel
- Vulnerability CriticalRUSTSEC-2021-0037 · 2021-03-05Fix a use-after-free bug in diesels Sqlite backend
- VulnerabilityRUSTSEC-2024-0365 · 2024-08-23Binary Protocol Misinterpretation caused by Truncating or Overflowing Casts
- UnsoundRUSTSEC-2026-0134 · 2026-04-24Unsound access to padding bytes while serializing date/time values using the Mysql backend
- UnsoundRUSTSEC-2026-0135 · 2026-04-24Unsound transmute while debug/display printing batch Insert statements in Diesel's SQLite backend
- VulnerabilityRUSTSEC-2026-0136 · 2026-04-24Command injection in Diesel's implementation of `COPY FROM`/`COPY TO`
- VulnerabilityRUSTSEC-2026-0137 · 2026-04-24Possible unaligned data access for implementations of `SqliteAggregate`
- UnsoundRUSTSEC-2026-0172 · 2026-06-05Possible use after free when deserializing a SQLite database via `SqliteConnection::deserialize_readonly_database`
Up next
Same cratediesel: security historyEvery advisory for this crate, and whether it is safe to use today.Read it next →Did this answer your question?