baserCMS is a website development framework. In versions 5.0.0 before 5.3.2 and 5.4.0 before 5.4.2, an authenticated user with only theme-file view permission can traverse outside the theme directory through the optional BcThemeFile plugin's Admin web screen. ThemeFilesController::parseArgs() constructs a path containing literal ../ segments, and the view and edit actions pass it to ThemeFilesService::get() without containment validation. Authorization checks the unresolved request path, after which ThemeFile::_getContents() reads the resolved file and exposes its contents in the form textarea. A client must preserve the dot segments rather than normalize them away. Readable files are limited to .php, .css, .js, and .ctp; this can disclose application source and config/install.php database credentials in MySQL or PostgreSQL deployments, while SQLite configurations have an empty database password. Reading config/app_local.php may expose the Security.salt fallback, which is effective only when not overridden by environment configuration. The flaw does not disclose .env, .pem, or SQLite .db files, does not itself permit file writes or code execution, and does not affect the separate API getFullpath() route. The plugin is disabled by default and unauthenticated requests are not sufficient. This issue has been patched in versions 5.3.2 and 5.4.2.