CVE-2026-3997: The Text Toggle plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'title' shortcode attribute of the [tt_part] and [tt] shortc...

Description

The Text Toggle plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'title' shortcode attribute of the [tt_part] and [tt] shortcodes in all versions up to and including 1.1. This is due to insufficient input sanitization and output escaping on user-supplied shortcode attributes. Specifically, in the avp_texttoggle_part_shortcode() function, the 'title' attribute is extracted from shortcode attributes and concatenated directly into HTML output without any escaping — both within an HTML attribute context (title="...") on line 116 and in HTML content on line 119. While the 'class' attribute is properly validated using ctype_alnum(), the 'title' attribute has no sanitization whatsoever. An attacker can inject double-quote characters to break out of the title attribute and inject arbitrary HTML attributes including event handlers. 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

0.25%

16.0th 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-2026-3997?

The Text Toggle plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'title' shortcode attribute of the [tt_part] and [tt] shortcodes in all versions up to and including 1.1. This is due to insufficient input sanitization and output escaping on user-supplied shortcode attributes. Specifically, in the avp_texttoggle_part_shortcode() function, the 'title' attribute is extracted from shortcode attributes and concatenated directly into HTML output without any escaping — both within an HTML attribute context (title="...") on line 116 and in HTML content on line 119. While the 'class' attribute is properly validated using ctype_alnum(), the 'title' attribute has no sanitization whatsoever. An attacker can inject double-quote characters to break out of the title attribute and inject arbitrary HTML attributes including event handlers. 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-2026-3997?

CVE-2026-3997 has a CVSS score of 6.4/10 (MEDIUM severity). The EPSS model estimates a 0.25% probability of exploitation in the next 30 days.

How do I fix CVE-2026-3997?

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.