The HTTP/2 implementation in HAProxy before 2.0.10 mishandles headers, as demonstrated by carriage return (CR, ASCII 0xd), line feed (LF, ASCII 0xa), and the zero character (NUL, ASCII 0x0), aka Intermediary Encapsulation Attacks.
git.haproxy.org/?p=haproxy-2.0.git%3Ba=commit%3Bh=ac198b92d461515551b95daae20954b3053ce87e
git.haproxy.org/?p=haproxy.git%3Ba=commit%3Bh=146f53ae7e97dbfe496d0445c2802dd0a30b0878
git.haproxy.org/?p=haproxy.git%3Ba=commit%3Bh=54f53ef7ce4102be596130b44c768d1818570344
seclists.org/bugtraq/2019/Nov/45
security.gentoo.org/glsa/202004-01
tools.ietf.org/html/rfc7540#section-10.3
usn.ubuntu.com/4212-1/
www.debian.org/security/2019/dsa-4577