Buffer overflow in the regular expression parser in PERL before 5.24.3-RC1 and 5.26.x before 5.26.1-RC1 allows remote attackers to cause a denial of service (crash) or leak data from memory via vectors involving use of RExC_parse in the vFAIL macro. https://nvd.nist.gov/vuln/detail/CVE-2017-12883