CVE-2023-6875: POST SMTP (WordPress plugin) · Insecure Direct Object Reference
Affects POST SMTP (WordPress plugin)Source CVE Database V5
Exposed hosts seen by OffSeq Mirage · public exploit available (Metasploit) · 90% EPSS · CVSS 9.8 Critical.
Data as of 25 Oct 2026, 19:02 UTC
- EPSS
- 90.3% chance of exploitation in 30 days – higher than 99% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 11 Jan 2024
Detectable: evidence found.
nuclei template: WordPress POST SMTP Mailer <= 2.8.7 - Authorization Bypass
Weaponised: evidence found.
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: evidence found.
1 exposed host found; no attack traffic recorded
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), OffSeq Mirage (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-25.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| wpexpertsio POST SMTP – The #1 WordPress SMTP Plugin with Advanced Email Logging and Delivery Failure Notifications | Affected
| Fixed in– |
AI-suggested
1. Immediate action should be to update the POST SMTP Mailer plugin to a version that addresses this vulnerability once available. 2. Implement strict access controls on the WordPress REST API endpoints, ensuring that only authenticated and authorized users can interact with sensitive plugin endpoints. 3. Monitor web server and WordPress logs for unusual POST requests to the connect-app endpoint, which may indicate exploitation attempts. 4. Conduct a thorough audit of email logs and reset API keys manually to prevent unauthorized access. 5. Employ multi-factor authentication (MFA) on WordPress admin accounts to reduce the risk of site takeover even if email credentials are compromised. 6. Educate site administrators about the risks of this vulnerability and encourage prompt application of security updates. 7. Consider deploying runtime application self-protection (RASP) or endpoint detection and response (EDR) solutions to detect and block exploitation attempts in real time. 8. Review and tighten overall WordPress security posture, including limiting plugin usage to trusted and actively maintained plugins.
Description
The POST SMTP Mailer – Email log, Delivery Failure Notifications and Best Mail SMTP for WordPress plugin for WordPress is vulnerable to unauthorized access of data and modification of data due to a type juggling issue on the connect-app REST endpoint in all versions up to, and including, 2.8.7. This makes it possible for unauthenticated attackers to reset the API key used to authenticate to the mailer and view logs, including password reset emails, allowing site takeover.
References
- wordfence.com/threat-intel/vulnerabilities/id/e675d64c-cbb8-4f24-9b6f-2597a97b49af?source=cve (opens in a new tab)
- plugins.trac.wordpress.org/browser/post-smtp/trunk/Postman/Mobile/includes/rest-api/v1/rest-api.php (opens in a new tab)
- plugins.trac.wordpress.org/changeset/3016051/post-smtp/trunk?contextall=1&old=3012318&old_path=%2Fpost-smtp%2Ftrunk (opens in a new tab)
- packetstormsecurity.com/files/176525/WordPress-POST-SMTP-Mailer-2.8.7-Authorization-Bypass-Cross-Site-Scripting.html (opens in a new tab)