---
id: CVE-2026-100702
title: >-
  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
summary: >-
  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 re…
severity: medium
cvss: 5.9
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-674
vendor: nodemailer
product: nodemailer
affected:
  - nodemailer < 10.0.2
published: '2026-09-26'
updated: '2026-09-26'
sourceUpdated: '2026-09-26T14:16:55.280'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-100702'
references:
  - url: >-
      https://github.com/nodemailer/nodemailer/security/advisories/GHSA-8vvx-rff5-p5rq
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/nodemailer-before-10.0.2-stack-exhaustion-via-nested-recipient-arrays
    label: disclosure@vulncheck.com
tags:
  - nvd
  - cve.org
ingestedAt: '2026-09-26T13:33:20.902Z'
---

## Overview

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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.