What is CVE-2026-90776?

CVE-2026-90776 is a high-severity vulnerability in Nodemailer, classified under Inefficient Algorithmic Complexity. CVSS score: 7.5/10. Published 2026-09-13.

How severe is CVE-2026-90776?

High severity. CVSS v3 base score is 7.5 out of 10.

Vulnerability in Nodemailer

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.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

Affected products

Nodemailer

Weakness classification (CWE)

CWE-407 — Inefficient Algorithmic Complexity

References

disclosure@vulncheck.com (vendor-advisory)
disclosure@vulncheck.com (patch)
disclosure@vulncheck.com (technical-description)
disclosure@vulncheck.com (release-notes)
disclosure@vulncheck.com (product)
disclosure@vulncheck.com (third-party-advisory)

Frequently asked questions

What is CVE-2026-90776?: CVE-2026-90776 is a high-severity vulnerability in Nodemailer, classified under Inefficient Algorithmic Complexity. CVSS score: 7.5/10. Published 2026-09-13.
How severe is CVE-2026-90776?: High severity. CVSS v3 base score is 7.5 out of 10.