[MEDIUM] Insert tag injection in front end forms

PKSA-bn7k-dnct-c6sd CVE-2020-25768 GHSA-f7wm-x4gw-6m23

Affected package: contao/core-bundle

Affected version: >=4.0.0,<4.4.52|>=4.5.0,<4.6.0|>=4.6.0,<4.7.0|>=4.7.0,<4.8.0|>=4.8.0,<4.9.0|>=4.9.0,<4.9.6|>=4.10.0,<4.10.1

Reported by:
FriendsOfPHP/security-advisories, GitHub