CVE-2026-16636
What it is
The FluentSMTP – WP SMTP Plugin with Amazon SES, SendGrid, MailGun, Postmark, Google and Any SMTP Provider plugin for WordPress is vulnerable to Stored Cross-Site Scripting via Recipient Display Name (to.name) in Email Logs in all versions up to, and including, 2.2.95 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. The payload is delivered via an attacker-controlled recipient display name (to.name) in a wp_mail() call and does not fire in the log list view — only in the detail view when an administrator uses the Prev/Next navigation controls, as that path bypasses the escapeHtml pipeline used by the list view.
At a glance
- Exploitability
- Can be exploited over the network without logging in. Limited direct impact.
- Exploit odds
- 0.5% chance of exploitation in the next 30 days (EPSS).
- Fix
- No patch or advisory is linked yet. Look at mitigations or restrict exposure.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Details
- Published
- Last modified
- Exploit probability
- 0.5% · EPSS, next 30 days
- Weakness
- CWE-79 · Cross-site scripting
- Record status
- Deferred
Attack profile CVSS 3.1 · 7.2
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
- Scope
- Changed
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N
References
- https://plugins.trac.wordpress.org/browser/fluent-smtp/tags/2.2.95/app/Models/Logger.php#L165
- https://plugins.trac.wordpress.org/browser/fluent-smtp/tags/2.2.95/app/Models/Logger.php#L310
- https://plugins.trac.wordpress.org/browser/fluent-smtp/tags/2.2.95/app/Services/Mailer/BaseHandler.php#L290
- https://plugins.trac.wordpress.org/browser/fluent-smtp/tags/2.2.95/app/Services/Mailer/BaseHandler.php#L357
- https://plugins.trac.wordpress.org/browser/fluent-smtp/tags/2.2.95/assets/admin/js/fluent-mail-admin-app.js
- https://plugins.trac.wordpress.org/changeset/3635135/fluent-smtp/trunk/assets/admin/js/fluent-mail-admin-app.js
- https://plugins.trac.wordpress.org/changeset?old_path=%2Ffluent-smtp/tags/2.2.95&new_path=%2Ffluent-smtp/tags/2.3.0
- https://plugins.trac.wordpress.org/changeset?reponame=&new=3635135%40fluent-smtp%2Ftags%2F2.3.0&old=3428610%40fluent-smtp%2Ftags%2F2.2.95
- https://www.wordfence.com/threat-intel/vulnerabilities/id/4ad3ed6b-19d4-47c7-a56c-54092c767fe9?source=cve