CVE-2023-6629: The POST SMTP Mailer – Email log, Delivery Failure Notifications and Best Mail SMTP for WordPress plugin for WordPress is vulnerable to Reflected Cros...

Description

The POST SMTP Mailer – Email log, Delivery Failure Notifications and Best Mail SMTP for WordPress plugin for WordPress is vulnerable to Reflected Cross-Site Scripting via the ‘msg’ parameter in all versions up to, and including, 2.8.6 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that execute if they can successfully trick a user into performing an action such as clicking on a link. CVE-2023-6621 appears to be a duplicate of this issue. CVE-2024-29128 appears to be a duplicate of this issue.

Metrics

CVSS 3.1

6.1/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

EPSS Probability

0.44%

35.3th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Wpexperts	Post Smtp	< 2.8.7

References

Timeline

Published: Jan 3, 2024
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2023-6629?

The POST SMTP Mailer – Email log, Delivery Failure Notifications and Best Mail SMTP for WordPress plugin for WordPress is vulnerable to Reflected Cross-Site Scripting via the ‘msg’ parameter in all versions up to, and including, 2.8.6 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that execute if they can successfully trick a user into performing an action such as clicking on a link. CVE-2023-6621 appears to be a duplicate of this issue. CVE-2024-29128 appears to be a duplicate of this issue.

How severe is CVE-2023-6629?

CVE-2023-6629 has a CVSS score of 6.1/10 (MEDIUM severity). The EPSS model estimates a 0.44% probability of exploitation in the next 30 days.

How do I fix CVE-2023-6629?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.