RobinHerbots Inputmask Internal Deep Merge Helper extend.js extendAliases prototype pollution

A vulnerability was found in RobinHerbots Inputmask up to 5.0.9. Affected by this issue is the function extendDefaults/extendDefinitions/extendAliases in the library lib/dependencyLibs/extend.js of the component Internal Deep Merge Helper. The manipulation results in improperly controlled modification of object prototype attributes. The attack may be performed from remote. The project was informed of the problem early through an issue report but has not responded yet.