Vulnerability · Published Sep 26, 2026 · Assigned by VulnCheck
CVE-2026-100700nodemailer before 10.0.6 Denial of Service via addressparser
High 7.5
In plain English
A high-severity security flaw in nodemailer from nodemailer. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 27% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
nodemailer before 10.0.6 contains a denial of service vulnerability in the addressparser free-text fallback regex pattern that exhibits quadratic backtracking behavior. Attackers can supply crafted email header values with long whitespace-free runs to block the Node.js event loop for tens of seconds, causing service unavailability.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | node-nodemailer | no fix listed | DEBIAN-CVE-2026-100700 |
| Debian:13 | node-nodemailer | no fix listed | DEBIAN-CVE-2026-100700 |
| Debian:14 | node-nodemailer | 10.0.10+~8.0.1-1 | DEBIAN-CVE-2026-100700 |
| Ubuntu:22.04:LTS | node-nodemailer | no fix listed | UBUNTU-CVE-2026-100700 |
| Ubuntu:24.04:LTS | node-nodemailer | no fix listed | UBUNTU-CVE-2026-100700 |
| Ubuntu:26.04:LTS | node-nodemailer | no fix listed | UBUNTU-CVE-2026-100700 |
| Ubuntu:26.10 | node-nodemailer | no fix listed | UBUNTU-CVE-2026-100700 |
| npm | nodemailer | 10.0.6 | GHSA-v53p-9fqp-m79j |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| nodemailer | nodemailer | 0 – before 10.0.6 |
Weakness: CWE-407 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
References
- GitHub Security Advisory (GHSA-v53p-9fqp-m79j) vendor-advisory
- VulnCheck Advisory: nodemailer before 10.0.6 Denial of Service via addressparser third-party-advisory