# CVE-2026-121425: Nodemailer addressparser recipient injection via group parsing

Source: https://junglewise.ai/threats/cve-2026-121425-nodemailer-from-3-0-0-before-10-1-4-contains-a-parsing-flaw-in  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-11-03. Updated: 2026-11-03  
License: CC BY 4.0 with a link back

CVE-2026-121425 · Severity: medium · CVSS 6.5 · Published 2026-11-03

Nodemailer is a Node.js library for sending emails. A parsing flaw in its address handling allows attackers to craft email addresses that bypass recipient validation checks, causing mail to be sent to attacker-controlled addresses instead of legitimate recipients. This enables mail interception and disclosure of sensitive content intended for approved recipients.

Technologies: [Nodemailer Project Nodemailer](https://junglewise.ai/threats/technologies/nodemailer-project-nodemailer). Vendors: [Nodemailer Project](https://junglewise.ai/threats/vendors/nodemailer-project).

## Quick answers

**Is CVE-2026-121425 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-121425 being exploited in the wild.

**How severe is CVE-2026-121425?** Medium severity, with a CVSS score of 6.5, published 3 November 2026.

**Which products and versions are affected?** Nodemailer Project Nodemailer 3.0.0 to 10.1.3.

**Is there a fix for CVE-2026-121425?** Yes: fixed in 10.1.4. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-121425 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-121425?** Check whether you run Nodemailer Project 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.

## How to fix

- Fixed in 10.1.4

## Technical details

The addressparser component incorrectly terminates RFC 5322 address groups at a semicolon appearing within quoted display names or comments, causing the text after the semicolon to be re-parsed as top-level recipients with inverted quoting. An attacker can craft addresses like G: (a; <evil@evil.com>) <v@victim.com>; which conformant RFC 5322 parsers read as v@victim.com but Nodemailer interprets as evil@evil.com, bypassing allowlist validation.

## Affected products

- Nodemailer Project Nodemailer 3.0.0 to 10.1.3

## Timeline

- 2026-10-19: disclosed
- 2026-11-03: advisory

## References

- [https://github.com/nodemailer/nodemailer/security/advisories/GHSA-m943-m63m-w62w](https://github.com/nodemailer/nodemailer/security/advisories/GHSA-m943-m63m-w62w)
- [https://www.vulncheck.com/advisories/nodemailer-3.0.0-before-10.1.4-recipient-injection-via-addressparser-group-parsing](https://www.vulncheck.com/advisories/nodemailer-3.0.0-before-10.1.4-recipient-injection-via-addressparser-group-parsing)

## Related threats

- [Nodemailer address parsing vulnerability in addressparser](https://junglewise.ai/threats/cve-2026-121426-nodemailer-from-3-0-0-before-10-1-4-contains-an-address-parsing)
- [Nodemailer address parser malformed recipient in RFC 5322 comments](https://junglewise.ai/threats/cve-2026-100699-nodemailer-is-a-node-js-email-sending-library-in-versions-9-1-0)