CVE-2026-27492: lettermint-node · Exposure of Data Element to Wrong Session
Affects lettermint-nodeSource CVE Database V5
Not known to be exploited · CVSS 4.7 Medium : upgrade to 1.5.1 when convenient.
Data as of 29 Oct 2026, 19:04 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 8% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 1.5.1
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:NExploitation evidence
Disclosed: evidence found.
CVE published 21 Feb 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.
What to do
Upgrade lettermint-node to 1.5.1.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| lettermintlettermint-node | Affected
| Fixed in
|
AI-suggested
To mitigate this vulnerability, organizations should immediately upgrade the Lettermint Node.js SDK to version 1.5.1 or later, where the issue is fixed. Developers should audit their email sending code to ensure that each email send operation uses a fresh client instance or explicitly resets all email properties before reuse. Implementing strict input validation and output sanitization for email content can reduce the risk of unintended data leakage. Additionally, segregate email sending contexts per user or transaction to avoid cross-contamination of data. Monitoring and logging email send operations can help detect anomalous behavior indicative of data leaks. Where possible, restrict access to the email sending functionality to trusted internal systems and users to limit the attack surface. Conduct regular code reviews and security testing focusing on session and state management in email-related components. Finally, educate developers about secure SDK usage patterns to prevent similar issues.
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.