Answer in brief
CVE-2021-32715 records a Medium severity (CVSS 5.3) vulnerability in Lenient `hyper` header parsing of `Content-Length` could allow request smuggling. The current sources do not mark it as known exploited. The current feed maps hyper (crates.io). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 5.3. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps hyper (crates.io). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| hypercrates.io | >=0.0.0-0 <0.14.10 | 0.14.10 |
Published upstream
Jul 7, 2021
Evidence: source:osv:source_dates:source-dates:recordSource modified
Oct 12, 2026
Evidence: source:osv:source_dates:source-dates:recordFirst seen by HOL
Oct 12, 2026
`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.
Quoted source text, attributed separately from HOL analysis.