It was discovered that the is-my-json-valid JavaScript library used an inefficient regular expression to validate JSON fields defined to have email format. A specially crafted JSON file could cause it to consume an excessive amount of CPU time when validated.

The is-my-json-valid package before 2.12.4 for Node.js has an incorrect exports['utc-millisec'] regular expression, which allows remote attackers to cause a denial of service (blocked event loop) via a crafted string.