Oniguruma before 6.9.3 allows Stack Exhaustion in regcomp.c because of recursion in regparse.c.
github.com/kkos/oniguruma/commit/4097828d7cc87589864fecf452f2cd46c5f37180
github.com/kkos/oniguruma/compare/v6.9.2...v6.9.3
github.com/kkos/oniguruma/issues/147
lists.debian.org/debian-lts-announce/2019/09/msg00010.html
lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/NWOWZZNFSAWM3BUTQNAE3PD44A6JU4KE/
lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZW47MSFZ6WYOAOFXHBDGU4LYACFRKC2Y/
usn.ubuntu.com/4460-1/