RUSTSEC-2023-0020: const-cstr is Unmaintained

What to do

1. Find who pulls it in: cargo tree -i const-cstr.
2. Avoid the affected API, or replace the crate.

Details from the advisory

Last release was about five years ago.

The maintainer(s) have been unreachable to respond to any issues that may or may not include security issues.

The repository is now archived and there is no security policy in place to contact the maintainer(s) otherwise.

No direct fork exist.

const-cstr is Unsound

The crate violates the safety contract of ffi::CStr::from_bytes_with_nul_unchecked used in ConstCStr::as_cstr

No interior nul bytes checking is done either by the constructor or the canonical macro to create the ConstCStr

const-cstr Panic

Additionally the crate may cause runtime panics if statically compiled and ran with any untrusted data that is not nul-terminated.

This is however unlikely but the the crate should not be used for untrusted data in context where panic may create a DoS vector.

Possible Alternatives

The below may or may not provide alternative(s)

• const_str::cstr!
• cstr::cstr!

References

• Package: crates.io/crates/const-cstr
• Advisory: rustsec.org/advisories/RUSTSEC-2023-0020.html
• Web: github.com/abonander/const-cstr

From the RustSec Advisory Database (CC0-1.0) via the OSV export, downloaded Oct 24, 2026. Severity score computed from the published CVSS vector.