{"action":"Upgrade typo3/cms-backend to 7.6.51 or later.","affected":[{"fixed":"7.6.51","introduced":"7.0.0"},{"fixed":"8.7.40","introduced":"8.0.0"},{"fixed":"9.5.25","introduced":"9.0.0"},{"fixed":"10.4.14","introduced":"10.0.0"},{"fixed":"11.1.1","introduced":"11.0.0"}],"component":"typo3/cms-backend","cve_ids":["CVE-2021-21370"],"ecosystem":"Packagist","epss":0.00872,"exploited":false,"fixed_versions":["7.6.51","8.7.40","9.5.25","10.4.14","11.1.1"],"ghsa_id":"GHSA-x7hc-x7fm-f7qh","id":"tcs_01M5KFAT4E6SJWHTDCKR5HNMPY","modified_at":"2026-07-08T06:27:52.429199044Z","published_at":"2021-03-23T01:54:17Z","references":["https://osv.dev/vulnerability/GHSA-x7hc-x7fm-f7qh","https://github.com/TYPO3/TYPO3.CMS/security/advisories/GHSA-x7hc-x7fm-f7qh","https://nvd.nist.gov/vuln/detail/CVE-2021-21370","https://github.com/FriendsOfPHP/security-advisories/blob/master/typo3/cms-core/CVE-2021-21370.yaml","https://github.com/FriendsOfPHP/security-advisories/blob/master/typo3/cms/CVE-2021-21370.yaml","https://packagist.org/packages/typo3/cms-backend","https://typo3.org/security/advisory/typo3-core-sa-2021-008"],"severity":{"label":"medium","score":5.4},"sources":[{"source":"osv","source_id":"GHSA-x7hc-x7fm-f7qh","url":"https://osv.dev/vulnerability/GHSA-x7hc-x7fm-f7qh"}],"summary":"Cross-Site Scripting in Content Preview (CType menu)"}