An issue was discovered in dns.c in HAProxy through 1.8.14. In the case of a compressed pointer, a crafted packet can trigger infinite recursion by making the pointer point to itself, or create a long chain of valid pointers resulting in stack exhaustion.
https://usn.ubuntu.com/3858-1/
https://lists.debian.org/debian-lts-announce/2022/05/msg00045.html
https://access.redhat.com/errata/RHSA-2019:1436
https://access.redhat.com/errata/RHBA-2019:0327
https://access.redhat.com/errata/RHBA-2019:0326
http://www.securityfocus.com/bid/106280
http://git.haproxy.org/?p=haproxy.git%3Ba=commit%3Bh=58df5aea0a0c926b2238f65908f5e9f83d1cca25