The issue is related to an unverified array indexing in the Duktape component of the Zabbix monitoring system. This can lead to a denial of service when exploited by a remote attacker. The problem occurs due to a bug in Duktape 2.6, which is a third-party embeddable JavaScript engine used for its portability and compact footprint. When too many values are added to the valstack in JavaScript, it will crash.