RUSTSEC-2026-0174: `Authorization::value` and `WwwAuthenticate::value` can violate ASCII invariants

What to do

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

Details from the advisory

Authorization::value uses HeaderValue::value with the claim that the internal string is ASCII, but Authorization::new and Authorization::set_credentials accept arbitrary String credentials without validation. As a result, safe code can construct a header value containing non-ASCII UTF-8 while the implementation assumes ASCII.

WwwAuthenticate::new and WwwAuthenticate::set_realm similarly accepts arbitrary String input, so WwwAuthenticate::value can also produce a header value that violates the crate’s documented ASCII invariants.

This issue has not been confirmed as Undefined Behavior, but the unsafe justification in Authorization::value and WwwAuthenticate::value appears incorrect and can produce values outside the expected ASCII-only constraints.

The http-types crate is unmaintained and the issue is unlikely to be fixed.

References

• Package: crates.io/crates/http-types
• Advisory: rustsec.org/advisories/RUSTSEC-2026-0174.html
• Report: github.com/http-rs/http-types/issues/534

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