tarteaucitron.js is a compliant and accessible cookie banner. A vulnerability was identified in tarteaucitron.js prior to 1.20.1, where the addOrUpdate function, used for applying custom texts, did not properly validate input. This allowed an attacker with direct access to the site's source code or a CMS plugin to manipulate JavaScript object prototypes, leading to potential security risks such as data corruption or unintended code execution. An attacker with high privileges could exploit this vulnerability to modify object prototypes, affecting core JavaScript behavior, cause application crashes or unexpected behavior, or potentially introduce further security vulnerabilities depending on the application's architecture. This vulnerability is fixed in 1.20.1.