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?

Medium severity, with a CVSS score of 6.5, published 23 October 2026.

Which products and versions are affected?

Nodemailer 3.0.0 through 10.1.3; nodemailer (npm) >= 3.0.0, < 10.1.4, SEMVER:introduced=3.0.0,fixed=10.1.4.

Is there a fix for This vulnerability?

Yes. nodemailer (npm): upgrade to 10.1.4 or later. 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.

Check whether you run Nodemailer or nodemailer (npm) 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.

Nodemailer addressparser angle-addr parsing bypass

Q: Is there a fix for This vulnerability?

Yes. nodemailer (npm): upgrade to 10.1.4 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

Q: How is This vulnerability attacked?

It is attacked over the network.

Q: Am I affected?

Check whether you run Nodemailer or nodemailer (npm) 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.

Severity: medium · CVSS 6.5 · Published 2026-10-23

Nodemailer, a library used by applications to send emails, contains a flaw in how it parses recipient addresses. An attacker can craft a malformed but technically valid email address that bypasses validation checks, causing emails intended for an allowed domain to be delivered to an attacker-controlled domain instead. This allows theft of email content that should have been restricted to authorized recipients.

Technologies: Nodemailer, nodemailer (npm). Vendors: Nodemailer, npm.

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?: Medium severity, with a CVSS score of 6.5, published 23 October 2026.
Which products and versions are affected?: Nodemailer 3.0.0 through 10.1.3; nodemailer (npm) >= 3.0.0, < 10.1.4, SEMVER:introduced=3.0.0,fixed=10.1.4.
Is there a fix for This vulnerability?: Yes. nodemailer (npm): upgrade to 10.1.4 or later. 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.
Am I affected?: Check whether you run Nodemailer or nodemailer (npm) 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

nodemailer (npm): upgrade to 10.1.4 or later
```
npm install nodemailer@10.1.4
```

Technical details

The addressparser component incorrectly terminates angle-bracket address parsing at the first `>` character encountered, even when that character appears inside a quoted local part, comment, or domain literal. This causes addresses like `<"a@evil.com>"@good.com>` to be misparsed as `"a@evil.com` at domain `evil.com`, while RFC 5322 conformant parsers correctly read it as `"a@evil.com>"@good.com`. An attacker can exploit this by submitting such an address through user-input forms that validate against a conformant parser but then pass the address to Nodemailer, bypassing domain allowlists and causing mail to be delivered to attacker-controlled domains.

Affected products

Nodemailer Nodemailer 3.0.0 through 10.1.3

Timeline

2026-10-23: disclosed
2026-10-18: other: vulnerability found in internal review

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