RUSTSEC-2021-0078Published

Lenient `hyper` header parsing of `Content-Length` could allow request smuggling

Exact source revision recorded 24 Oct 2026 13:19:54 UTC. It does not establish the source's current position. Latest evidence.

Recorded JSON

osv · RUSTSEC-2021-0078

Published

`hyper`'s HTTP header parser accepted, according to RFC 7230, illegal contents inside `Content-Length` headers. Due to this, upstream HTTP proxies that ignore the header may still forward them along if it chooses to ignore the error. To be vulnerable, `hyper` must be used as an HTTP/1 server and using an HTTP proxy upstream that ignores the header's contents but still forwards it. Due to all the factors that must line up, an attack exploiting this vulnerability is unlikely.

Source published: 7 Jul 2021 12:00:00 UTC
Source modified: 12 Oct 2026 18:00:03 UTC
Observed here: 24 Oct 2026 13:19:54 UTC
Source terms: OSV · upstream source license applies

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · OSV · upstream source license applies. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS_V3 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N