CVE-2026-27492 MEDIUM

CVE-2026-27492: Lettermint Node.js SDK leaks email properties to unintended recipients when client instance is reused

Vendor Lettermint
Product lettermint-node
Weakness CWE-488
Published February 21, 2026
Last update February 24, 2026

CVSS base score

4.7/10
Attack vector Local
Attack complexity High
Privileges required Low
User interaction None
Confidentiality High
Integrity None

CVSS vector

CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N

What the vulnerability does

01Description

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.

Key dates

02Disclosure timeline

February 21, 2026 CVE published
February 24, 2026 Record updated