Perl is a highly capable, feature-rich programming language.
S_regmatch() function lacks proper checks before passing arguments to atoi()
A remote attacker could send a specially crafted input, possibly resulting in a Denial of Service condition.
There is no known workaround at this time.
All Perl users should upgrade to the latest version:
# emerge --sync
# emerge --ask --oneshot --verbose ">=dev-lang/perl-5.20.1-r4"