---
id: CVE-2026-90776
title: >-
  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
summary: >-
  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-separ…
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-407
  - CWE-1333
vendor: nodemailer
product: nodemailer
affected:
  - nodemailer >= 9.1.0 < 10.0.5
published: '2026-09-13'
updated: '2026-09-16'
sourceUpdated: '2026-09-16T15:18:42.833'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-90776'
references:
  - url: 'https://github.com/nodemailer/nodemailer'
    label: disclosure@vulncheck.com
  - url: >-
      https://github.com/nodemailer/nodemailer/blob/v10.0.4/src/addressparser/index.ts#L251
    label: disclosure@vulncheck.com
  - url: >-
      https://github.com/nodemailer/nodemailer/commit/c07f17518d25aca8ab2ad66968dcbca538c24b89
    label: disclosure@vulncheck.com
  - url: 'https://github.com/nodemailer/nodemailer/releases/tag/v10.0.5'
    label: disclosure@vulncheck.com
  - url: >-
      https://github.com/nodemailer/nodemailer/security/advisories/GHSA-prgh-xp8r-p3m5
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/nodemailer-9.1.0-through-10.0.4-denial-of-service-via-quadratic-address-parsing
    label: disclosure@vulncheck.com
  - url: >-
      https://github.com/nodemailer/nodemailer/security/advisories/GHSA-prgh-xp8r-p3m5
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-90776.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-90776'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2532697'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-90776'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-90776'
tags:
  - nvd
  - cve.org
  - exploit-available
  - csaf
  - vex
  - red-hat
epss: 0.00479
epssPercentile: 0.40494
exploitAvailable: true
ssvc:
  exploitation: poc
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-09-16T14:04:25.782469Z'
ingestedAt: '2026-09-14T15:23:07.470Z'
---

## Overview

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.

## Remediation

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

## Vendor advisories

- **Red Hat VEX** · Important · affected: Self-service automation portal 2 · no fix planned: Self-service automation portal 2 · updated 2026-09-15 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-90776.json)