Inefficient Algorithmic Complexity Affecting nodemailer package, versions <9.1.0
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Test your applications- Snyk IDSNYK-JS-NODEMAILER-19651822
- published9 Sept 2026
- disclosed8 Sept 2026
- creditEric Labrador Sainz
Introduced: 8 Sep 2026
New CVE NOT AVAILABLE CWE-407 (opens in a new tab)How to fix?
Upgrade nodemailer to version 9.1.0 or higher.
Overview
nodemailer is an Easy as cake e-mail sending from your Node.js applications
Affected versions of this package are vulnerable to Inefficient Algorithmic Complexity through the addressparser function in lib/addressparser/index.js. An attacker can block the Node.js event loop by supplying a crafted comma-separated address list, such as a To, Cc, Bcc, From, or Reply-To header value, that forces the parser to spend CPU time proportional to the square of the input size. This stalls email processing and delays or freezes every other request handled by the same process.