{"cve":"CVE-2026-4335","nvd":{"published":"2026-03-26T04:17:12.810","modified":"2026-06-17T10:56:26.343","status":"Deferred","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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N","score":5.4},"cwes":["CWE-79"],"references":["https://plugins.trac.wordpress.org/browser/shortpixel-image-optimiser/tags/6.4.3/class/Controller/AjaxController.php#L449","https://plugins.trac.wordpress.org/browser/shortpixel-image-optimiser/tags/6.4.3/class/view/snippets/media-popup.php#L139","https://plugins.trac.wordpress.org/browser/shortpixel-image-optimiser/trunk/class/Controller/AjaxController.php#L449","https://plugins.trac.wordpress.org/browser/shortpixel-image-optimiser/trunk/class/view/snippets/media-popup.php#L139","https://plugins.trac.wordpress.org/changeset?sfp_email=&sfph_mail=&reponame=&old=3490270%40shortpixel-image-optimiser&new=3490270%40shortpixel-image-optimiser&sfp_email=&sfph_mail="],"products":[],"source":"nvd","synced_at":"2026-10-19T22:28:18.033120106+00:00"},"epss":{"cve":"CVE-2026-4335","score":0.00179,"percentile":0.07511,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}