H3 is a minimal H(TTP) framework built for high performance and portability. Prior to 1.15.5, there is a critical HTTP Request Smuggling vulnerability. readRawBody is doing a strict case-sensitive check for the Transfer-Encoding header. It explicitly looks for "chunked", but per the RFC, this header should be case-insensitive. This vulnerability is fixed in 1.15.5.
Exploitability
AV:NAC:HPR:NUI:NScope
S:CImpact
C:HI:HA:L8.9/CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:LOther