This affects the package latte/latte before 2.10.6. There is a way to bypass allowFunctions that will affect the security of the application. When the template is set to allow/disallow the use of certain functions, adding control characters (x00-x08) after the function will bypass these restrictions.
https://snyk.io/vuln/SNYK-PHP-LATTELATTE-1932226
https://github.com/nette/latte/issues/279
https://github.com/nette/latte/commit/227c86eda9a8a6d060ea8501923e768b6d992210