ShortPixel Image Optimizer <= 6.4.3 - Authenticated (Author+) Stored Cross-Site Scripting via Attachment Title
Summary
| CVE | CVE-2026-4335 |
|---|---|
| State | PUBLISHED |
| Assigner | Wordfence |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-03-26 04:17:12 UTC |
| Updated | 2026-03-30 13:26:50 UTC |
| 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. |
Risk And Classification
Primary CVSS: v3.1 5.4 MEDIUM from [email protected]
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
EPSS: 0.000370000 probability, percentile 0.110320000 (date 2026-04-02)
Problem Types: CWE-79 | CWE-79 CWE-79 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | [email protected] | Primary | 5.4 | MEDIUM | CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N |
| 3.1 | CNA | DECLARED | 5.4 | MEDIUM | CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N |
CVSS v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
LowPrivileges Required
LowUser Interaction
RequiredScope
ChangedConfidentiality
LowIntegrity
LowAvailability
NoneCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Shortpixel | ShortPixel Image Optimizer Optimize Images Convert WebP AVIF | affected * 6.4.3 semver | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| plugins.trac.wordpress.org/changeset | [email protected] | plugins.trac.wordpress.org | |
| plugins.trac.wordpress.org/browser/shortpixel-image-optimiser/tags/6.4.3/class/view/snip... | [email protected] | plugins.trac.wordpress.org | |
| plugins.trac.wordpress.org/browser/shortpixel-image-optimiser/trunk/class/view/snippets/... | [email protected] | plugins.trac.wordpress.org | |
| www.wordfence.com/threat-intel/vulnerabilities/id/a156234f-2644-4d17-aaa5-4f088... | [email protected] | www.wordfence.com | |
| plugins.trac.wordpress.org/browser/shortpixel-image-optimiser/tags/6.4.3/class/Controlle... | [email protected] | plugins.trac.wordpress.org | |
| plugins.trac.wordpress.org/browser/shortpixel-image-optimiser/trunk/class/Controller/Aja... | [email protected] | plugins.trac.wordpress.org | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: daroo (en)
Additional Advisory Data
| Source | Time | Event |
|---|---|---|
| CNA | 2026-03-17T14:30:57.000Z | Vendor Notified |
| CNA | 2026-03-25T00:00:00.000Z | Disclosed |
There are currently no legacy QID mappings associated with this CVE.