ShortPixel Image Optimizer <= 6.4.3 - Authenticated (Author+) Stored Cross-Site Scripting via Attachment Title
| CVE | CVE-2026-4335 |
|---|---|
| CVSS | 5.4 (Medium) |
| Publicly Published | March 25, 2026 |
| Last Updated | March 26, 2026 |
| Researcher |
daroo
|
Description
The ShortPixel Image Optimizer plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the attachment post_title in all versions up to, and including, 6.4.3. This is due to insufficient output escaping in the getEditorPopup() function and its corresponding media-popup.php template. Specifically, the attachment's post_title is retrieved from the database via get_post() in AjaxController.php (line 435) and passed directly to the view template (line 449), where it is rendered into an HTML input element's value attribute without esc_attr() escaping (media-popup.php line 139). Since WordPress allows Authors to set arbitrary attachment titles (including double-quote characters) via the REST API, a malicious author can craft an attachment title that breaks out of the HTML attribute and injects arbitrary JavaScript event handlers. This makes it possible for authenticated attackers, with Author-level access and above, to inject arbitrary web scripts that execute whenever a higher-privileged user (such as an administrator) opens the ShortPixel AI editor popup (Background Removal or Image Upscale) for the poisoned attachment.
Learn more about Cross-Site Scripting vulnerabilities and how to prevent them.
References
- plugins.trac.wordpress.org
- plugins.trac.wordpress.org
- plugins.trac.wordpress.org
- plugins.trac.wordpress.org
- plugins.trac.wordpress.org
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Vulnerability Details for ShortPixel Image Optimizer – Optimize Images, Convert WebP & AVIF
| Software Type | Plugin |
|---|---|
| Software Slug | shortpixel-image-optimiser (view on wordpress.org) |
| Patched? | Yes |
| Remediation | Update to version 6.4.4, or a newer patched version |
| Affected Version |
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| Patched Version |
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Recent vulnerabilities in ShortPixel Image Optimizer – Optimize Images, Convert WebP & AVIF
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