Perl before 5.30.3 on 32-bit platforms allows a heap-based buffer overflow because nested regular expression quantifiers have an integer overflow.
Exploitability
AV:NAC:LPR:NUI:NScope
S:UImpact
C:NI:LA:H8.2/CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H