CVE-2026-16636 json
FluentSMTP <= 2.2.95 - Unauthenticated Stored Cross-Site Scripting via Recipient Display Name (to.name) in Email Logs
published 2026-08-06 3 mo ago modified 2026-08-12 2 mo ago also EUVD-2026-53702
- cvss
- 7.2
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.5%
- EPSS 0.5% chance of exploitation in 30 days, percentile 45%
- public exploits
- 0
- none known
Summary
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.
CISA SSVC
- Exploitation
- none
- Automatable
- yes
- Technical impact
- partial
- Assessed
- 3 mo ago
Exploit prediction
0.53% chance of exploitation in the next 30 days, higher than 45% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 7.2 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N |
Affected products
- wpmanageninja FluentSMTP – WP SMTP Plugin with Amazon SES, SendGrid, Mailgun, Postmark, Cloudflare, toSend, Gmail and Any SMTP
Classification
- Weakness
-
- CWE-79 Improper Neutralization of Input During Web Page Generation
- Technology feeds
References
- wordfence.com /threat-intel/vulnerabilities/id/4ad3ed6b-19d4-47c7-a56c-54092c767fe9?source=cve
- plugins.trac.wordpress.org /browser/fluent-smtp/tags/2.2.95/assets/admin/js/fluent-mail-admin-app.js
- plugins.trac.wordpress.org /browser/fluent-smtp/tags/2.2.95/app/Services/Mailer/BaseHandler.php#L357
- plugins.trac.wordpress.org /browser/fluent-smtp/tags/2.2.95/app/Models/Logger.php#L165
- plugins.trac.wordpress.org /browser/fluent-smtp/tags/2.2.95/app/Models/Logger.php#L310
- plugins.trac.wordpress.org /browser/fluent-smtp/tags/2.2.95/app/Services/Mailer/BaseHandler.php#L290
- plugins.trac.wordpress.org /changeset?reponame=&new=3635135%40fluent-smtp%2Ftags%2F2.3.0&old=3428610%40fluent-smtp%2Ftags%2F2.2.95
- plugins.trac.wordpress.org /changeset/3635135/fluent-smtp/trunk/assets/admin/js/fluent-mail-admin-app.js
- plugins.trac.wordpress.org /changeset?old_path=%2Ffluent-smtp/tags/2.2.95&new_path=%2Ffluent-smtp/tags/2.3.0
Sources
- CVE List CVE-2026-16636
- NVD CVE-2026-16636
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.