Stored Cross-Site Scripting Vulnerability in FluentSMTP Plugin for WordPress
CVE-2026-16636

7.2HIGH

Key Information:

Vendor

WordPress
Status
Fluentsmtp – WP Smtp Plugin With Amazon Ses, Sendgrid, Mailgun, Postmark, Cloudflare, Tosend, Gmail And Any Smtp
Vendor
CVE Published:
6 August 2026

What is CVE-2026-16636?

The FluentSMTP plugin for WordPress contains a vulnerability that allows for Stored Cross-Site Scripting (XSS) through the recipient display name in email logs. This issue arises due to insufficient input sanitization and output escaping, enabling unauthenticated attackers to inject malicious scripts. The exploitation occurs not in the log list view but in the detail view accessed through navigation controls, bypassing necessary safety mechanisms. This could lead to the execution of arbitrary web scripts when an administrator views the details of logged emails, potentially compromising site security and user data.

Affected Version(s)

FluentSMTP – WP SMTP Plugin with Amazon SES, SendGrid, Mailgun, Postmark, Cloudflare, toSend, Gmail and Any SMTP 0 <= 2.2.95

References

https://www.wordfence.com/threat-intel/vulnerabilities/id...
https://plugins.trac.wordpress.org/browser/fluent-smtp/ta...
https://plugins.trac.wordpress.org/browser/fluent-smtp/ta...

CVSS V3.1

Score:
7.2
Severity:
HIGH
Confidentiality:
Low
Integrity:
Low
Availability:
Low
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Changed

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Fraudless
.