FluentSMTP <= 2.2.95 - Unauthenticated Stored Cross-Site Scripting via Recipient Display Name (to.name) in Email Logs
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Cross-site scripting
- Confidentiality · integrity · availability
- Low · Low · None
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-79.
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| WP ManageNinja LLC | FluentSMTP – WP SMTP Plugin with Amazon SES, SendGrid, Mailgun, Postmark, Cloudflare, toSend, Gmail and Any SMTP | up to 2.2.95 | — | No fix listed | CNA |
- FluentSMTP – WP SMTP Plugin with Amazon SES, SendGrid, Mailgun, Postmark, Cloudflare, toSend, Gmail and Any SMTP VendorWP ManageNinja LLC Affected up to 2.2.95 Fixed in — No fix listed CNA
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2026-16636
- 2026-10-03 Alias added: GHSA-v4r4-2fwc-5qq5
References
Other 9
- https://www.wordfence.com/threat-intel/vulnerabilities/id/4ad3ed6b-19d4-47c7-a56c-54092c767fe9?source=cve
- 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/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/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/changeset?reponame=&new=3635135%40fluent-smtp%2Ftags%2F2.3.0&old=3428610%40fluent-smtp%2Ftags%2F2.2.95
- 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
More WP ManageNinja LLC vulnerabilities
- TI-2021-13634 CSRF in WP Fluent Forms < 3.6.67 allows stored XSS and Privilege Escalation CVSS 3.1HIGH 8.8
- TI-2022-04342 FluentAuth < 1.0.2 - Bypass blocks by IP Spoofing CVSS 3.1HIGH 7.5
- TI-2024-11836 Ninja Tables < 5.0.17 - Admin+ Stored XSS CVSS 3.1MEDIUM 6.1
- TI-2023-00211 FluentSMTP < 2.2.3 - Stored XSS via Email Logs CVSS 3.1MEDIUM 5.4
- TI-2026-51633 Ninja Tables Pro 5.2.11 Embedded Malicious Code via Tampered Plugin Build CVSS 4.0CRITICAL 9.3
- TI-2026-51632 Fluent Forms Pro 6.2.7 Embedded Malicious Code via Tampered Plugin Build CVSS 4.0CRITICAL 9.3
Sources
- CVE-2026-16636 · CVE Program
- CVE-2026-16636 · NVD
- FIRST EPSS
- GHSA-v4r4-2fwc-5qq5 · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences