The WordPress plugin 'GS Books Showcase – Display Books in Grid, Slider & More | Library for WordPress' versions up to 1.3.1 contain a stored cross-site scripting vulnerability (CVE-2024-11766) due to improper neutralization of input during web page generation. Specifically, the 'gs_book_showcase' shortcode does not adequately sanitize or escape user-supplied attributes, enabling authenticated attackers with contributor-level or higher privileges to inject arbitrary JavaScript code. This code executes in the context of any user who accesses the page containing the injected shortcode, potentially leading to session hijacking or other script-based attacks. The CVSS 3.1 base score is 6.4, reflecting network attack vector, low attack complexity, required privileges, no user interaction, and partial confidentiality and integrity impact. No patch or vendor advisory is currently available, and the plugin is not a cloud service.

An attacker with contributor-level or higher privileges can inject persistent malicious scripts into pages via the vulnerable shortcode. These scripts execute in the browsers of users who view the affected pages, potentially compromising user sessions or data confidentiality and integrity. The vulnerability does not affect availability. There are no reports of active exploitation 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 disabling or removing the vulnerable plugin to prevent exploitation. Monitor for updates from the plugin vendor or WordPress security channels for an official patch or mitigation instructions.