An issue was discovered in Perl 5.18 through 5.26. A crafted regular expression can cause a heap-based buffer overflow, with control over the bytes written.
https://www.oracle.com/security-alerts/cpujul2020.html
https://www.debian.org/security/2018/dsa-4172
https://usn.ubuntu.com/3625-1/
https://security.gentoo.org/glsa/201909-01
https://rt.perl.org/Public/Bug/Display.html?id=132227
https://access.redhat.com/errata/RHSA-2018:1192