Perl before 5.26.3 and 5.28.x before 5.28.1 has a buffer overflow via a crafted regular expression that triggers invalid write operations.
https://www.oracle.com/technetwork/security-advisory/cpujul2019-5072835.html
https://www.oracle.com/security-alerts/cpujul2020.html
https://www.oracle.com/security-alerts/cpuapr2020.html
https://www.debian.org/security/2018/dsa-4347
https://usn.ubuntu.com/3834-2/
https://usn.ubuntu.com/3834-1/
https://support.apple.com/kb/HT209600
https://security.netapp.com/advisory/ntap-20190221-0003/
https://security.gentoo.org/glsa/201909-01
https://seclists.org/bugtraq/2019/Mar/42
https://rt.perl.org/Ticket/Display.html?id=133204
https://metacpan.org/changes/release/SHAY/perl-5.28.1
https://metacpan.org/changes/release/SHAY/perl-5.26.3
https://lists.debian.org/debian-lts-announce/2018/11/msg00039.html
https://kc.mcafee.com/corporate/index?page=content&id=SB10278
https://github.com/Perl/perl5/commit/34716e2a6ee2af96078d62b065b7785c001194be
https://bugzilla.redhat.com/show_bug.cgi?id=1646730
https://access.redhat.com/errata/RHSA-2019:2400
https://access.redhat.com/errata/RHSA-2019:1942
https://access.redhat.com/errata/RHSA-2019:1790
https://access.redhat.com/errata/RHSA-2019:0109
https://access.redhat.com/errata/RHSA-2019:0010
https://access.redhat.com/errata/RHSA-2019:0001
https://access.redhat.com/errata/RHBA-2019:0327
http://www.securitytracker.com/id/1042181