CVE-2026-27492

Lettermint Node.js SDK leaks email properties to unintended recipients when client instance is reused

Published Feb 21, 2026 CVSS 3.1 · 4.7 Medium EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-49pc-8936-wvfp Lettermint Node.js SDK leaks email properties to unintended recipients when client instance is reused
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Lettermint lettermint
CPEs cpe:2.3:a:lettermint:lettermint:*:*:*:*:*:node.js:*:*
Vendors & Products Lettermint lettermint
Type Values Removed Values Added
First Time appeared Lettermint
Lettermint lettermint-node
Vendors & Products Lettermint
Lettermint lettermint-node
Type Values Removed Values Added
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.
Title Lettermint Node.js SDK leaks email properties to unintended recipients when client instance is reused
Weaknesses CWE-488
References
Metrics cvssV3_1

{'score': 4.7, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Feb 24, 2026, 6:08 PM
Reserved
Feb 19, 2026, 7:46 PM
Status
Analyzed
Published
Feb 21, 2026, 11:15 AM
Modified
Jun 17, 2026, 10:27 AM