CVE-2026-27492

Medium

Description

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.

SeverityMedium
CVSS4.7
Exploit probability—
ProductLettermint
PublishedFeb 21, 2026
First seenFeb 21, 2026
Weakness typeCWE-488CWE-488

How to fix

Update
  • lettermint lettermint1.5.1 or later
  • lettermint1.5.1 or later

Affected products

ProductAffected versionsFixed in
lettermint lettermintv < 1.5.11.5.1
lettermintnpmv < 1.5.11.5.1

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