Is CVE-2026-121426 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-121426 being exploited in the wild.

How severe is CVE-2026-121426?

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 before 10.1.4.

Is there a fix for CVE-2026-121426?

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-2026-121426 attacked?

It is attacked over the network, in a software library.

Am I affected by CVE-2026-121426?

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.

CVE-2026-121426: Nodemailer address parsing vulnerability in addressparser

CVE-2026-121426 · Severity: medium · CVSS 6.5 · Published 2026-11-03

Nodemailer is a Node.js library used by applications to send email messages. This vulnerability allows attackers to craft email addresses that bypass recipient allow lists by tricking the parser into delivering messages to an attacker-controlled domain instead of the intended recipient. An attacker exploiting this could intercept and read sensitive email content that an application intended for a different domain.

Technologies: Nodemailer Project Nodemailer. Vendors: Nodemailer Project.

Quick answers

Is CVE-2026-121426 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-121426 being exploited in the wild.
How severe is CVE-2026-121426?: 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 before 10.1.4.
Is there a fix for CVE-2026-121426?: 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-2026-121426 attacked?: It is attacked over the network, in a software library.
Am I affected by CVE-2026-121426?: 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 angle-addr parsing at the first '>' character it encounters, even when that character appears within a quoted local part, comment, or domain literal. This causes addresses like <"a@evil.com>"@good.com> to be parsed as evil.com instead of good.com. An attacker with control over email addresses (such as in contact forms or inbound message headers) can submit RFC 5322-compliant addresses that validate against allow lists but deliver to attacker-controlled domains.

Affected products

Nodemailer Project Nodemailer 3.0.0 before 10.1.4

Timeline

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

References

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