CVE-2026-90776

Nodemailer versions 9.1.0 through 10.0.4 contain a quadratic time complexity vulnerability in the addressparser component when parsing email addresses with RFC 5322 comments. Attackers can craft malicious email headers with comment-separated atoms to consume excessive CPU and block the Node.js event loop for several seconds, causing denial of service.

  • Published Sep 13, 2026
  • CVSS 8.7 high
  • 0.7% chance of exploitation in the next 30 days (EPSS)
  • A fix is available

Affected software

CVE-2026-90776 at the National Vulnerability Database