GitHub Advisoryadvisory · crates.io
GHSA-h5x4-m2qf-r4f2 Diesel's SQLite backend has possible UTF-8 corruption
HIGH
Official page ↗
- Ecosystem
- crates.io
- Packages
- diesel
- Severity
- High
- CVSS vector
- CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N
- Weaknesses
- CWE-20
- Reviewed
- 2026-05-05
Affected packages
• crates.io diesel: < 2.3.8 → fixed in 2.3.8
Description
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.
Related
Weakness · CWE (1)
- CWE-20 Improper Input Validation weakness