Plugins · fluent-smtp · data as of 2026-11-01
Is FluentSMTP safe? Known vulnerabilities and latest version
- Latest version
- 2.4.1
- Last updated
- 2026-09-27
- Active installs
- 700,000+
- Known issues on record
- 4
- Unpatched in latest
- 0
- Tested up to WP
- 7.1.4 · PHP 7.4+
Free WP Mail SMTP plugin. Fix WordPress email deliverability with Gmail, Amazon SES, SendGrid, Mailgun, Postmark, Cloudflare, Brevo or any SMTP. — by WPManageNinja
What to do
- Update to the latest version (2.4.1). Anything older than 2.3.0 has at least one known issue listed below. Dashboard → Updates, or Plugins → “update now”.
- If you cannot update right away, deactivate it until you can.
- Turn on auto-updates for it: Plugins → “Enable auto-updates” on its row.
- If you ran a vulnerable version and something looks off (spam pages, strange admins, redirects), run the free scan.
With WP-CLI: wp plugin get fluent-smtp --field=version shows what you run; wp plugin update fluent-smtp updates it.
Check your version
Known vulnerabilities
4 on record, newest first. “Affected” is the version range the source gives; “fixed in” is the version the source names, or (marked *) the first wordpress.org release after the last affected version.
high 7.2 CVE-2026-16636 · published 2026-08-06
Stored cross-site scripting (XSS) in FluentSMTP (2.2.95 and older)
- Affected
- 2.2.95 and older
- Fixed in
- 2.3.0 *
- Access needed (per CVSS)
- No login needed
- Range from
- CVE record (the advisory publisher) · score by Wordfence
Details from the advisory
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.
NVD CVE-2026-16636Wordfence advisoryCode change (fix)Plugin source
medium 4.3 CVE-2025-24739 · published 2025-01-24
Cross-site request forgery (CSRF) in FluentSMTP (2.2.80 and older)
- Affected
- 2.2.80 and older
- Fixed in
- 2.2.81
- Access needed (per CVSS)
- No login needed; someone on the site has to click a link or open a page
- Range from
- CVE record (the advisory publisher) · score by Patchstack
Details from the advisory
Cross-Site Request Forgery (CSRF) vulnerability in Shahjahan Jewel FluentSMTP fluent-smtp allows Cross Site Request Forgery.This issue affects FluentSMTP: from n/a through <= 2.2.80.
critical 9.8 CVE-2024-9511 · published 2024-11-23
PHP object injection in FluentSMTP (2.2.82 and older)
- Affected
- 2.2.82 and older
- Fixed in
- 2.2.83 *
- Access needed (per CVSS)
- No login needed
- Range from
- CVE record (the advisory publisher) · score by Wordfence
Details from the advisory
The FluentSMTP – WP SMTP Plugin with Amazon SES, SendGrid, MailGun, Postmark, Google and Any SMTP Provider plugin for WordPress is vulnerable to PHP Object Injection in all versions up to, and including, 2.2.82 via deserialization of untrusted input in the 'formatResult' function. This makes it possible for unauthenticated attackers to inject a PHP Object. No known POP chain is present in the vulnerable software. If a POP chain is present via an additional plugin or theme installed on the target system, it could allow the attacker to delete arbitrary files, retrieve sensitive data, or execute code. The vulnerability was partially patched in version 2.2.82.
NVD CVE-2024-9511Wordfence advisoryCode change (fix)Plugin source
medium 6.1 CVE-2023-3087 · published 2023-07-12
Stored cross-site scripting (XSS) in FluentSMTP (2.2.4 and older)
- Affected
- 2.2.4 and older
- Fixed in
- 2.2.5 *
- Access needed (per CVSS)
- No login needed; someone on the site has to click a link or open a page
- Range from
- CVE record (the advisory publisher) · score by NVD
Details from the advisory
The FluentSMTP plugin for WordPress is vulnerable to Stored Cross-Site Scripting via an email subject in versions up to, and including, 2.2.4 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.
Recent activity
- 2026-09-27 — latest release on wordpress.org (2.4.1).
- 2026-08-06 — Stored cross-site scripting (XSS) disclosed (CVE-2026-16636), fixed in 2.3.0.
- 2025-01-24 — Cross-site request forgery (CSRF) disclosed (CVE-2025-24739), fixed in 2.2.81.
- 2024-11-23 — PHP object injection disclosed (CVE-2024-9511), fixed in 2.2.83.
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Where this data comes from
- Version, last update, installs: wordpress.org/plugins/fluent-smtp (Plugins API), fetched 2026-11-01.
- Vulnerabilities: NIST National Vulnerability Database (NVD), checked 2026-11-01. This product uses data from the NVD API but is not endorsed or certified by the NVD.
- Each record links to its CVE page and to the original advisory (Wordfence, Patchstack or WPScan) where there is one. We only list a CVE here when its references or its advisory name this exact plugin, so a few real issues may be missing; none should be about a different plugin. Spot an error? Email Daniel.
Badge for your site or docs (states facts with a date, not a verdict):
<a href="https://laskyr.com/plugins/fluent-smtp"><img src="https://laskyr.com/plugins/fluent-smtp/badge.svg" alt="FluentSMTP vulnerability status"></a>