Security Alert Summary
The KIA Subtitle plugin for WordPress is affected by a stored Cross-Site Scripting (XSS) vulnerability (CVE-2026-7509). Insufficient input sanitization and output escaping of the the-subtitle shortcode attributes before and after allow authenticated users with Contributor-level access and above to inject HTML or script that will be stored and executed when other users view the affected page.
CVE Details
- CVE ID: CVE-2026-7509
- Affected component: KIA Subtitle plugin for WordPress
- Affected versions: All versions up to and including 4.0.1
- Published: May 22, 2026 5:16:27 AM UTC
- Last modified: May 22, 2026 5:16:27 AM UTC
- CVSS v3.1: Base Score 6.4, Severity MEDIUM; Vector:
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N- Attack Vector: NETWORK
- Attack Complexity: LOW
- Privileges Required: LOW (authenticated user, e.g., Contributor-level or higher)
- User Interaction: NONE
- Scope: CHANGED
- Confidentiality Impact: LOW
- Integrity Impact: LOW
- Availability Impact: NONE
- Authentication/Privileges/User Interaction: Requires an authenticated user with Contributor-level privileges or higher; no user interaction required beyond visiting an affected page
- Primary impact: Confidentiality – LOW; Integrity – LOW; Availability – NONE
- CWE: CWE-79 (Improper Neutralization of Input During Web Page Generation or XSS)
Technical Details
This issue is a stored Cross-Site Scripting vulnerability in the plugin’s the-subtitle shortcode. The plugin accepts user-supplied values for the shortcode attributes before and after and does not perform sufficient input sanitization or output escaping, allowing an authenticated user to insert arbitrary HTML or script into the saved page content. When another user views the page, the injected script is rendered and executed in the context of the site.
The vulnerability exists because attribute values passed to the shortcode are not properly neutralized before being included in page output. The CVE description indicates the problem is attributable to insufficient input sanitization and output escaping of those attributes. No additional functions or REST endpoints are named in the provided data.
Impact is limited to actions enabled by stored XSS: execution of attacker-supplied scripts in the browsers of users who view the affected page. This can be used to modify how a page appears to a user, capture data available to the browser (for example, cookies accessible via JavaScript, or content on the page), or perform actions on behalf of the viewing user within the constraints of their browser session and privileges.
How This Could Impact Your Website
Consider a site where multiple people have editorial access: a site owner, internal staff editors, and external contributors or contractors. A contributor who can create or edit content could add malicious markup to a page using the the-subtitle shortcode attributes. When an editor or the site owner views that page in the admin area or on the front end, the injected script could run in their browser.
Practical consequences include exposure of internal user information visible in the browser, such as email addresses displayed on pages, or information present on the page that could be harvested by injected scripts. This increases the risk of targeted phishing or social engineering against staff whose details are exposed. The vulnerability does not, based on the provided information, imply automatic full site compromise, but it does raise the risk of credential theft or session-related attacks if other protections are not in place.
professional review If you’re unsure whether your site is affected or how to assess your current user roles and plugins, it may be worth having a professional review your setup.
Recommended Actions
- Update the affected plugin as soon as a patched version is available.
- Review and reduce unnecessary user roles, especially Contributor-level accounts that can submit or edit content.
- Enforce strong passwords and two-factor authentication for editors and administrators.
- Remove unused or unmaintained plugins from your site.
- Monitor site activity and logs for unusual behavior, including unexpected content changes or new pages.
If you’d like help reviewing your plugins, user roles, or overall WordPress security posture, our team at Freshy is happy to help.
References
- https://plugins.trac.wordpress.org/browser/kia-subtitle/tags/4.0.1/kia-subtitle.php#L329
- https://plugins.trac.wordpress.org/browser/kia-subtitle/tags/4.0.1/kia-subtitle.php#L359
- https://plugins.trac.wordpress.org/browser/kia-subtitle/tags/4.0.2/kia-subtitle.php#L369
- https://plugins.trac.wordpress.org/browser/kia-subtitle/tags/4.0.2/kia-subtitle.php#L370
- https://plugins.trac.wordpress.org/browser/kia-subtitle/trunk/kia-subtitle.php#L329
- https://plugins.trac.wordpress.org/browser/kia-subtitle/trunk/kia-subtitle.php#L359
- https://www.wordfence.com/threat-intel/vulnerabilities/id/a9a52097-0d85-4036-9b74-f35fea549607?source=cve
