CVE-2025-13963 identifies a stored cross-site scripting vulnerability in the falselight FX Currency Converter WordPress plugin, specifically in the 'fxcc_convert' shortcode. The issue is due to improper neutralization of input during web page generation, allowing authenticated contributors or higher to inject arbitrary scripts via user-supplied shortcode attributes. This vulnerability affects all versions up to and including 0.2.0. The CVSS 3.1 base score is 6.4, reflecting network attack vector, low attack complexity, privileges required at the contributor level, no user interaction, and impacts on confidentiality and integrity with no availability 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 malicious scripts into pages using the vulnerable shortcode. These scripts execute in the context of users visiting the infected pages, potentially compromising user data confidentiality and integrity. There is no impact on availability. The vulnerability could facilitate actions such as session hijacking or unauthorized actions performed by users viewing the injected content. No known active exploitation has been reported.

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 FX Currency Converter plugin if possible. Monitor for updates from the vendor or WordPress plugin repository regarding patches or mitigations.