CVE-2021-23400

CVE-2021-23400 is a high-severity HTTP Header Injection vulnerability affecting nodemailer versions prior to 6.6.1. It allows an attacker to inject malicious headers if unsanitized user input containing newlines or carriage returns is used in an address object. This vulnerability carries a CVSS score of 8.8, indicating a high potential for impact including confidentiality, integrity, and availability compromise, and requires user interaction. While no public exploits or active exploitation have been observed, and community discussion is minimal, organizations using affected nodemailer versions should update immediately.