htp_parse_authorization_digest in htp_parsers.c in LibHTP 0.5.26 allows remote attackers to cause a heap-based buffer over-read via an authorization digest header.
In OISF LibHTP before 0.5.31, as used in Suricata 4.1.4 and other products, an HTTP protocol parsing error causes the http_header signature to not alert on a response with a single \r\n ending.
LibHTP is a security-aware parser for the HTTP protocol. Crafted traffic can cause excessive processing time of HTTP headers, leading to denial of service. This issue is addressed in 0.5.46.