CVE-2026-27492 — Lettermint Node.js SDK leaks email properties to unintended recipients when client instance is reused
Lettermint Node.js SDK is the official Node.js SDK for Lettermint. In versions 1.5.0 and below, email properties (such as to, subject, html, text, and attachments) are not reset…
Published: 2026-02-21 · CVSS: 4.7 · CVSS 3.1
Lettermint Node.js SDK is the official Node.js SDK for Lettermint. In versions 1.5.0 and below, email properties (such as to, subject, html, text, and attachments) are not reset between sends when a single client instance is reused across multiple .send() calls. This can cause properties from a previous send to leak into a subsequent one, potentially delivering content or recipient addresses to unintended parties. Applications sending emails to different recipients in sequence — such as transactional flows like password resets or notifications — are affected. This issue has been fixed in version 1.5.1.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7