It has been discovered that link tags generated by typolink
functionality are vulnerable to cross-site scripting - properties being assigned as HTML attributes have not been parsed correctly.
Update to TYPO3 versions 9.5.17 or 10.4.2 that fix the problem described.
github.com/FriendsOfPHP/security-advisories/blob/master/typo3/cms-core/CVE-2020-11065.yaml
github.com/FriendsOfPHP/security-advisories/blob/master/typo3/cms/CVE-2020-11065.yaml
github.com/TYPO3/TYPO3.CMS/security/advisories/GHSA-4j77-gg36-9864
nvd.nist.gov/vuln/detail/CVE-2020-11065
typo3.org/security/advisory/typo3-core-sa-2020-003