Nodemailer up to 10.0.8 Address Parser src/addressparser input validation

Summaryinfo

A vulnerability classified as problematic was found in Nodemailer up to 10.0.8. This vulnerability affects unknown code of the file src/addressparser of the component Address Parser. Such manipulation leads to input validation. This vulnerability is uniquely identified as CVE-2026-100699. The attack can be launched remotely. No exploit exists. Upgrading the affected component is advised.

Detailsinfo

A vulnerability was found in Nodemailer up to 10.0.8. It has been rated as problematic. Affected by this issue is an unknown function of the file src/addressparser of the component Address Parser. The manipulation with an unknown input leads to a input validation vulnerability. Using CWE to declare the problem leads to CWE-20. The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly. Impacted is integrity. CVE summarizes:

Nodemailer is a Node.js email-sending library. In versions >= 9.1.0 and < 10.0.9, the address parser (src/addressparser) mishandles addresses whose local-part is a quoted string and that are followed by RFC 5322 comments, allowing trailing comment-separated domain atoms to be retained in the normalized address. For example, the input "user"@example.com(x)evil.com is parsed to the address value '[email protected] evil.com', which contains additional attacker-controlled domain text separated by a literal space. This parsed value is used without further strict recipient validation when the message envelope is built (envelope.to in src/mime-node), so a malformed/ambiguous recipient address can be accepted and placed in the SMTP envelope. Whether this results in delivery to an unintended recipient on real SMTP servers has not been confirmed. The issue is a variant of the RFC 5322 comment parsing problem addressed in GHSA-cc9r-2j5m-2m83, affecting the separate quoted-local-part code path. Version 10.0.9 contains a fix.

The advisory is shared for download at github.com. This vulnerability is handled as CVE-2026-100699 since 09/26/2026. The exploitation is known to be easy. The attack may be launched remotely. No form of authentication is required for exploitation. There are known technical details, but no exploit is available.

Upgrading to version 10.0.9 eliminates this vulnerability.

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Productinfo

Name

• Nodemailer

Version

• 10.0.0
• 10.0.1
• 10.0.2
• 10.0.3
• 10.0.4
• 10.0.5
• 10.0.6
• 10.0.7
• 10.0.8

Website

• Product: https://github.com/nodemailer/nodemailer/

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