CVE-2026-3659: The WP Circliful plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'id' shortcode attribute of the [circliful] shortcode and v...

Description

The WP Circliful plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'id' shortcode attribute of the [circliful] shortcode and via multiple shortcode attributes of the [circliful_direct] shortcode in all versions up to and including 1.2. This is due to insufficient input sanitization and output escaping on user-supplied shortcode attributes. Specifically, in the circliful_shortcode() function, the 'id' attribute value is concatenated directly into an HTML id attribute (line 285) without any escaping, allowing an attacker to break out of the double-quoted attribute and inject arbitrary HTML event handlers. Similarly, the circliful_direct_shortcode() function (line 257) outputs all shortcode attributes directly into HTML data-* attributes without 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

0.32%

24.0th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-79

References

Timeline

Published: Apr 15, 2026
Last Modified: Jun 17, 2026
Status: Deferred

Frequently Asked Questions

What is CVE-2026-3659?

The WP Circliful plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'id' shortcode attribute of the [circliful] shortcode and via multiple shortcode attributes of the [circliful_direct] shortcode in all versions up to and including 1.2. This is due to insufficient input sanitization and output escaping on user-supplied shortcode attributes. Specifically, in the circliful_shortcode() function, the 'id' attribute value is concatenated directly into an HTML id attribute (line 285) without any escaping, allowing an attacker to break out of the double-quoted attribute and inject arbitrary HTML event handlers. Similarly, the circliful_direct_shortcode() function (line 257) outputs all shortcode attributes directly into HTML data-* attributes without 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-2026-3659?

CVE-2026-3659 has a CVSS score of 6.4/10 (MEDIUM severity). The EPSS model estimates a 0.32% probability of exploitation in the next 30 days.

How do I fix CVE-2026-3659?

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.