CVE-2026-3554: The Sherk Custom Post Type Displays plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'title' shortcode attribute in all versi...

Description

The Sherk Custom Post Type Displays plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'title' shortcode attribute in all versions up to, and including, 1.2.1. This is due to insufficient input sanitization and output escaping on the 'title' attribute of the 'sherkcptdisplays' shortcode. Specifically, in the sherkcptdisplays_func() function in includes/SherkCPTDisplaysShortcode.php, the 'title' attribute value is extracted from shortcode_atts() on line 19 and directly concatenated into an HTML <h2> tag on line 31 without any escaping. This makes it possible for authenticated attackers, with Contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

Metrics

CVSS 3.1

6.4/10

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

EPSS Probability

0.20%

10.5th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-79

References

Timeline

Published: Mar 21, 2026
Last Modified: Jun 17, 2026
Status: Deferred

Frequently Asked Questions

What is CVE-2026-3554?

The Sherk Custom Post Type Displays plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'title' shortcode attribute in all versions up to, and including, 1.2.1. This is due to insufficient input sanitization and output escaping on the 'title' attribute of the 'sherkcptdisplays' shortcode. Specifically, in the sherkcptdisplays_func() function in includes/SherkCPTDisplaysShortcode.php, the 'title' attribute value is extracted from shortcode_atts() on line 19 and directly concatenated into an HTML <h2> tag on line 31 without any escaping. This makes it possible for authenticated attackers, with Contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

How severe is CVE-2026-3554?

CVE-2026-3554 has a CVSS score of 6.4/10 (MEDIUM severity). The EPSS model estimates a 0.20% probability of exploitation in the next 30 days.

How do I fix CVE-2026-3554?

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.