Nodemailer interpretation conflict in email address parsing

Severity: high · CVSS 7.5 · Published 2025-11-14

Nodemailer is a popular library used by Node.js applications to send emails. A vulnerability in how it handles recipient addresses allows an attacker to craft a special email address that tricks the system into sending messages to an unintended external domain. This can result in sensitive data being leaked to an attacker and may allow them to bypass security filters or access controls that rely on domain-based rules.

Technologies: Nodemailer. Vendors: Nodemailer.

Quick answers

Is This vulnerability exploited in the wild?
No. Junglewise Threat Intelligence has no report of This vulnerability being exploited in the wild.
How severe is This vulnerability?
High severity, with a CVSS score of 7.5, published 14 November 2025.
Which products and versions are affected?
Nodemailer < 7.0.7.
Is there a fix for This vulnerability?
A patch was published on 2025-11-17: Version 7.0.7 released and duplicate advisory withdrawn Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is This vulnerability attacked?
It is attacked over the network, in a software library.
Am I affected?
Check whether you run Nodemailer at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

A vulnerability exists in Nodemailer's address parser (specifically handling quoted local-parts) due to an interpretation conflict (CWE-436). When a recipient address contains an '@' symbol inside a quoted string (e.g., '"user@attacker.com"@internal.domain'), the parser may incorrectly prioritize the embedded address, routing the email to the attacker's domain instead of the RFC-compliant target domain. This allows for remote, unauthenticated data exfiltration or security filter evasion. The issue is fixed in version 7.0.7 by improving the handling of quoted nested email addresses to align with RFC 5321/5322.

Affected products

  • Nodemailer nodemailer < 7.0.7

Timeline

  • 2025-10-05: advisory: Original advisory GHSA-mm7p-fcc7-pg87 published
  • 2025-11-14: disclosed: CVE-2025-13033 published
  • 2025-11-17: patched: Version 7.0.7 released and duplicate advisory withdrawn

References

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