CVE-2023-6875
CriticalExploitedPOST SMTP Mailer – Email log, Delivery Failure Notifications and Best Mail SMTP for WordPress <= 2.8.7 - Authorization Bypass via type connect-app API
Published Jan 12, 2024 · Updated Aug 12, 2026 · Also known as e675d64c-cbb8-4f24-9b6f-2597a97b49af
Key Facts
Patch immediately- CVE-2023-6875 is a critical-severity vulnerability (CVSS 9.8 v3.1) affecting Post Smtp (Wpexperts), Post SMTP – Complete Email Deliverability and SMTP Solution with Email Logs, Alerts, Backup SMTP & Mobile App.
- It is exploited in the wild, listed in Industry KEV feed, CIRCL KEV since Jan 10, 2024. No public exploit code is known.
- EPSS estimates a 90% probability of exploitation in the next 30 days.
- Fixed versions are available, including Post Smtp 2.8.8, Post Smtp 2.8.7.
- Brandefense priority: patch immediately, because it is listed as exploited in the wild.
CVSS v3.1
9.8
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS (30-day exploit likelihood)
90%
Higher than 99.8% of all scored CVEs
Exploited in the wild
Yes
2 catalog listings
Public exploit code
None known
Get the full CVE-2023-6875 brief as a PDF
Every affected product and fixed release, exploitation status and a first 24 hours response checklist, emailed within minutes.
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. CVE-2023-52233 appears to be a duplicate of this issue.
Known-Exploited Catalog Listings
| Catalog | Added | Remediation due | Ransomware use |
|---|---|---|---|
| Industry KEV feed | Jan 10, 2024 | n/a | Not reported |
| CIRCL KEV | Jan 18, 2026 | n/a | Not reported |
Required action: Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.
Affected Products
3 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| Post SmtpWpexperts | See advisory | 2.8.7 |
| Post SMTP – Complete Email Deliverability and SMTP Solution with Email Logs, Alerts, Backup SMTP & Mobile App | See advisory | n/a |
Patched Releases
Post Smtp
2.8.8, 2.8.7
Timeline
Added to Industry KEV feed
Jan 10, 2024
Publicly disclosed
Jan 12, 2024
Added to CIRCL KEV
Jan 18, 2026
Last updated
Aug 12, 2026
Weakness Type
- CWE-639 Authorization Bypass Through User-Controlled Key
- CWE-862 Missing Authorization
References
- advisoryhttp://packetstormsecurity.com/files/176525/WordPress-POST-SMTP-Mailer-2.8.7-Authorization-Bypass-Cross-Site-Scripting.html
- advisoryhttps://github.com/CVEProject/cvelistV5/tree/main/cves/2023/6xxx/CVE-2023-6875.json
- advisoryhttps://nvd.nist.gov/vuln/detail/CVE-2023-6875
- advisoryhttps://nvd.nist.gov/vuln/detail/CVE-2023-7070
- advisoryhttps://plugins.trac.wordpress.org/browser/email-encoder-bundle/trunk/core/includes/classes/class-email-encoder-bundle-run.php#L518
FAQ
Common Questions.
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.
Affected: Post Smtp (Wpexperts); Post SMTP – Complete Email Deliverability and SMTP Solution with Email Logs, Alerts, Backup SMTP & Mobile App. The full list is in the CVE brief.
It is exploited in the wild, listed in Industry KEV feed, CIRCL KEV since Jan 10, 2024.
No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.
No public exploit code is known.
Fixed versions are available, including Post Smtp 2.8.8, Post Smtp 2.8.7.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.
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