The regex code in Webkit 2.4.11 allows remote attackers to cause a denial of service (memory consumption) as demonstrated in a large number of ($ (open parenthesis and dollar) followed by {-2,16} and a large number of +) (plus close parenthesis).
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2016-9643.json"
[ { "events": [ { "introduced": "0" }, { "last_affected": "2.4.11" } ] } ]