Vulnerability in Nodemailer

CVE-2026-100702

Nodemailer before 10.0.2 fails to properly flatten deeply nested arrays in recipient fields such as to, cc, and bcc, allowing attackers to cause stack exhaustion. Attackers can supply a deeply nested JSON recipient array that triggers recursive Array.toString() conversion, exhausting the call stack and terminating the Node.js process.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 5.9 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-100702?
CVE-2026-100702 is a medium-severity vulnerability in Nodemailer, classified under Uncontrolled Recursion. CVSS score: 5.9/10. Published 2026-09-26.
How severe is CVE-2026-100702?
Medium severity. CVSS v3 base score is 5.9 out of 10.