CVE-2026-4082 is a stored cross-site scripting vulnerability in the ER Swiffy Insert WordPress plugin. The issue arises from insufficient input sanitization and lack of output escaping on shortcode attributes 'n', 'w', and 'h' used in the [swiffy] shortcode. These attributes are extracted and directly interpolated into HTML output without escaping functions like esc_attr(), enabling authenticated users with Contributor or higher privileges to inject arbitrary JavaScript code. This vulnerability affects all versions up to and including 1.0.0 of the plugin. The CVSS 3.1 base score is 6.4, reflecting a medium severity with network attack vector, low attack complexity, and requiring privileges but no user interaction.

An attacker with Contributor-level or higher access can inject malicious scripts into pages via the vulnerable shortcode attributes. These scripts execute in the context of users who view the infected pages, potentially leading to session hijacking, defacement, or other client-side attacks. The vulnerability does not impact availability and requires authenticated access, limiting its scope somewhat. There are no known exploits in the wild at this time.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is released, restrict Contributor-level access to trusted users only and consider removing or disabling the ER Swiffy Insert plugin to prevent exploitation. Monitor for updates from the vendor or plugin maintainers regarding patches or official mitigations.