Regular expression Denial-of-Service (ReDoS) exists in multiple add-ons for Mailform Pro CGI 4.3.1.3 and earlier, which allows a remote unauthenticated attacker to cause a denial-of-service condition. Affected add-ons are as follows: call/call.js, prefcodeadv/search.cgi, estimate/estimate.js, search/search.js, suggest/suggest.js, and coupon/coupon.js.