POST SMTP Mailer – Email log, Delivery Failure Notifications and Best Mail SMTP for WordPress <= 2.8.7 — Authorization Bypass via type connect-app API
CVE-2023-6875Published · Updated Action summary
Affected: ≤2.8.7Update to 2.8.8 or newer
All remediation steps- Severity
- Critical9.8
- CVSS
- 9.8CVSS 3.1 · CNA (Wordfence)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HWhat does this vector mean?
AV:NAttack vector- Network
AC:LAttack complexity- Low
PR:NPrivileges required- None
UI:NUser interaction- None
S:UScope- Unchanged
C:HConfidentiality- High
I:HIntegrity- High
A:HAvailability- High
- Required access
- No account needed
- Exploit prediction (EPSS)
- No score
- CISA KEV
- Not listed
On this page8
Am I affected?
- Affected≤ 2.8.7
- Patched in2.8.8
Update to 2.8.8 or newer.
You are affected if you run ≤ 2.8.7. Version 2.8.8 and later are not affected by this issue.
- Check your version: in wp-admin go to Plugins → Installed Plugins and read the version under Post SMTP – Complete Email Delivery and SMTP Solution with Email Logs, Alerts, Backup SMTP & Mobile App.
- No admin access? Run a passive check of your site. It reads public files only.
- No account is needed to exploit this. Treat any exposed site on an affected version as at risk.
What to do
- Update to version 2.8.8, or a newer patched version
- Rotate administrator passwords and application secrets if the site ran a vulnerable version while publicly reachable.
- Watch Post SMTP – Complete Email Delivery and SMTP Solution with Email Logs, Alerts, Backup SMTP & Mobile App to get an email when the next vulnerability is published.
Advisory
Source description from Wordfence Intelligence, credited to Ulyses Saicha.
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.
Exploits & references
Proof-of-concept & detection
No public proof-of-concept or detection template is known for this vulnerability.
Advisories & patches
- Advisorywordfence.com
Related CVEs
More in Post SMTP – Complete Email Delivery and SMTP Solution with Email Logs, Alerts, Backup SMTP & Mobile App
All 28| Severity | Vulnerability | CVE | Published |
|---|---|---|---|
| High7.2 | Unauthenticated Stored DOM-Based Cross-Site Scripting via 'user_email' Parameter (Multisite Registration → Failed Email Log) ≤4.0.1Update to 4.0.2 | CVE-2026-75962 | |
| Medium6.3 | Missing Authorization to Authenticated (Subscriber+) Settings Change 4.0.0-beta.1 – 4.0.0-beta.1Update to 4.0.1 | CVE-2026-81278 | |
| High7.2 | Unauthenticated Stored Cross-Site Scripting ≤3.6.2Update to 3.6.3 | CVE-2026-48838 | |
| Medium6.1 | Reflected DOM-Based Cross-Site Scripting via url Parameter ≤5.5.8Update to 5.5.9 | CVE-2024-13362 | |
| High7.2 | Unauthenticated Stored Cross-Site Scripting via 'event_type' ≤3.8.0Update to 3.9.0 | CVE-2026-3090 |
- High7.2Unauthenticated Stored DOM-Based Cross-Site Scripting via 'user_email' Parameter (Multisite Registration → Failed Email Log)
≤4.0.1Update to 4.0.2
- Medium6.3Missing Authorization to Authenticated (Subscriber+) Settings Change
4.0.0-beta.1 – 4.0.0-beta.1Update to 4.0.1
- High7.2Unauthenticated Stored Cross-Site Scripting
≤3.6.2Update to 3.6.3
- Medium6.1Reflected DOM-Based Cross-Site Scripting via url Parameter
≤5.5.8Update to 5.5.9
- High7.2Unauthenticated Stored Cross-Site Scripting via 'event_type'
≤3.8.0Update to 3.9.0
Timeline
CVE published
Severity critical, CVSS 9.8
Record last updated
Sources & licenses
Wordfence record- Vulnerability data
- Wordfence Intelligence. [object Object] Licensed under the CC BY-SA 4.0.
- CVE® identifiers
- [object Object]. Used under the CVE Program. CVE® is a registered trademark of The MITRE Corporation.
- CVSS / CWE
- National Vulnerability Database (NVD), shown unmodified. This product uses the NVD API but is not endorsed or certified by the NVD.
- VulnCrest content
- Summary, remediation guidance and page layout © VulnCrest. Not sourced from NVD.
