CVE-2026-2300 is a stored cross-site scripting vulnerability in the BJ Lazy Load WordPress plugin (versions up to 1.0.9). The issue stems from the filter_images() function using preg_replace for HTML processing that fails to correctly handle HTML attribute boundaries, specifically when replacing src attributes. This flaw allows crafted content inside a class attribute to be elevated to real DOM attributes, enabling authenticated users with Contributor-level permissions or higher to inject arbitrary JavaScript into pages. The vulnerability has a CVSS 3.1 base score of 6.4 (medium severity) with network attack vector, low attack complexity, and no user interaction required. No official patch or remediation level has been published by the vendor.

An authenticated attacker with Contributor-level or higher privileges can inject persistent malicious scripts into web pages via the vulnerable filter_images() function. These scripts execute in the context of users viewing the compromised pages, potentially leading to information disclosure or session hijacking. The vulnerability does not affect availability and requires some privileges to exploit. There are no reports of active exploitation in the wild.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is released, limit Contributor-level access to trusted users only. Consider disabling or replacing the BJ Lazy Load plugin if feasible to reduce exposure.