Inefficient Algorithmic Complexity Affecting nodemailer package, versions >=3.0.0 <10.0.10
Threat Intelligence
Snyk has a proof-of-concept or detailed explanation of how to exploit this vulnerability.
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-JS-NODEMAILER-20953004
- published15 Oct 2026
- disclosed15 Oct 2026
- creditmanus-pi, manus-use
Introduced: 15 Oct 2026
NewCVE-2026-110872 (opens in a new tab)How to fix?
Upgrade nodemailer to version 10.0.10 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 in the isPartialResponse function and the _onData method of SMTPConnection in src/smtp-connection/index.ts, where each continuation line is appended to the same response queue entry and the partial check re-runs str.slice(str.lastIndexOf('\n') + 1) over the whole accumulated string, forcing a full flatten of the V8 rope on every line. An attacker who controls or impersonates the SMTP peer can starve the event loop of the entire Node.js process, halting every other connection, request, and timer in it, and grow memory without bound, by streaming continuation lines such as 220-flood and never sending a completion line. This is reachable during the greeting and EHLO phases before the client authenticates or issues any command, the connection module applies no cap on accumulated reply size or line count, and the existing timers do not help, since greetingTimeout fires into an already starved loop and the inactivity socketTimeout resets on every inbound chunk.