Description
Nodemailer from 3.0.0 before 10.0.10 contains a quadratic complexity denial of service vulnerability in the SMTP client reply parser in SMTPConnection._onData and isPartialResponse. A malicious SMTP server or on-path attacker can stream continuation lines without a completion line before authentication, blocking the Node.js event loop and exhausting memory.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| nodemailer | nodemailer | 3.0.0 – < 10.0.10 | 10.0.10 |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | node-nodemailer | 10.0.10+~8.0.1-1 | — |
| Debian 13 | node-nodemailer | No fix yet | — |
| Debian 12 | node-nodemailer | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | node-nodemailer | No fix yet | — |
| Ubuntu 26.04 LTS | node-nodemailer | No fix yet | — |
| Ubuntu 24.04 LTS | node-nodemailer | No fix yet | — |
| Ubuntu 22.04 LTS | node-nodemailer | No fix yet | — |
| Ubuntu 20.04 LTS | node-nodemailer | No fix yet | — |
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| npm | nodemailer | >= 3.0.0, < 10.0.10 | 10.0.10 | GHSA-4g23-2xm8-66gc |
References
- GitHub Security Advisory (GHSA-4g23-2xm8-66gc) vendor-advisory
- VulnCheck Advisory: Nodemailer 3.0.0 before 10.0.10 Denial of Service via SMTP Reply Parsing third-party-advisory