curl: HTTP/3 Protocol Smuggling and Header Injection via CRLF in QPACK value conversion

A fundamental design flaw exists in how libcurl handles HTTP/3 QUIC response headers across all supported backends ngtcp2, quiche, openssl-quic. The vulnerability stems from the unsafe transcoding of binary QPACK headers HTTP/3 into the textual HTTP/1.1 format used internally by curl's pipeline...