RUSTSEC-2022-0022: Parser creates invalid uninitialized value

What to do

1. See which version you have: cargo tree -i hyper (it also shows which of your dependencies pulls it in).
2. Update within your version requirement: cargo update -p hyper. If the fix is a newer major or minor than your requirement allows, raise it in Cargo.toml (for example hyper = "0.14.12") or update the dependency that pulls it in.
3. Check again with cargo audit, or paste your Cargo.lock into our Cargo.toml checker.

Details from the advisory

Affected versions of this crate called mem::uninitialized() in the HTTP1 parser to create values of type httparse::Header (from the httparse crate). This is unsound, since Header contains references and thus must be non-null.

The flaw was corrected by avoiding the use of mem::uninitialized(), using MaybeUninit instead.

References

• Package: crates.io/crates/hyper
• Advisory: rustsec.org/advisories/RUSTSEC-2022-0022.html
• Web: github.com/hyperium/hyper/pull/2545

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 hyper

• Vulnerability MediumRUSTSEC-2016-0002 · 2016-05-09HTTPS MitM vulnerability due to lack of hostname verification
• Vulnerability MediumRUSTSEC-2017-0002 · 2017-01-23headers containing newline characters can split messages
• Vulnerability CriticalRUSTSEC-2020-0008 · 2020-03-19Flaw in hyper allows request smuggling by sending a body in GET requests
• Vulnerability HighRUSTSEC-2021-0020 · 2021-02-05Multiple Transfer-Encoding headers misinterprets request payload
• Vulnerability MediumRUSTSEC-2021-0078 · 2021-07-07Lenient `hyper` header parsing of `Content-Length` could allow request smuggling
• Vulnerability CriticalRUSTSEC-2021-0079 · 2021-07-07Integer overflow in `hyper`'s parsing of the `Transfer-Encoding` header leads to data loss

Full security history of hyper