CVE-2026-66731 facil.io 0.7.5 - 0.7.6 HTTP/1.1 Chunked Transfer Encoding Parser Crash DoS

facil.io 0.7.5 through 0.7.6 contains a denial-of-service vulnerability in the HTTP/1.1 chunked transfer encoding parser that allows unauthenticated remote attackers to crash the server by sending a negative chunk size value. Attackers can send a single POST request with a Transfer-Encoding:...

CVE-2026-66731

facil.io 0.7.5–0.7.6 contains a remote DoS in the HTTP/1.1 chunked transfer encoding parser. The vulnerability arises when a negative chunk size value is sent via a Transfer-Encoding: chunked header, causing http1_parser.h to negate the size, compute a large positive value, corrupt internal state...