Nodemailer: Quoted local-part can produce malformed envelope recipient through RFC 5322 comment parsing — GHSA-G57G-F23G-4646

Summary

## Summary Nodemailer's address parser can produce an unexpected recipient address when an RFC 5322 comment follows the domain of an address whose local-part is a quoted string. For example: ```text "user"@example.com(x)evil.com ``` is parsed as: ```text { address: "user@example.com evil.com", name: "" } ``` The resulting address therefore contains additional attacker-controlled domain text separated by a literal…

Timeline

Published by source

2026-09-29

Risk context

• Reported severity or threat level: medium.
• Reported CVSS score: 5.3 out of 10.
• Review exposure for the affected product or family: npm: nodemailer.

Product

npm: nodemailer

What to do

General, cautious steps (verify details in the official source):

• Review exposure and plan remediation based on risk and environment.
• Identify affected product versions in your inventory and verify whether you are impacted.
• Apply vendor patches/updates or recommended mitigations as soon as available.
• Read the official advisory for exact affected versions and remediation steps.

Official advisory

• Read the official source

Evidence and provenance

Canonical advisory ID

GHSA-G57G-F23G-4646

Source

GitHub

Vendor

GitHub

Published by source

2026-09-29

Last source activity

2026-09-29

Curated by

hlukh.ch

Related advisories and connections

These advisories are connected by shared CVE, product, vendor, source, or time signals.