{"id":"CVE-2021-21340","aliases":["BIT-typo3-2021-21340","GHSA-fjh3-g8gq-9q92"],"url":"https://o3.security/vulnerability/CVE-2021-21340","summary":"Cross-Site Scripting in Content Preview","details":"### Problem\nIt has been discovered that database fields used as _descriptionColumn_ are vulnerable to cross-site scripting when their content gets previewed in the page module. A valid backend user account is needed to exploit this vulnerability.\n\n### Solution\nUpdate to TYPO3 versions 10.4.14, 11.1.1 that fix the problem described.\n\n### Credits\nThanks to Richie Lee who reported this issue and to TYPO3 framework merger Andreas Fernandez who fixed the issue.\n\n### References\n* [TYPO3-CORE-SA-2021-007](https://typo3.org/security/advisory/typo3-core-sa-2021-007)","published":"2021-03-23T02:15:12.533Z","modified":"2026-08-27T08:40:24.426974Z","cvss":{"score":5.4,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N"},"epss":null,"cisaKev":null,"exploitsKnown":null,"affectedPackages":[{"ecosystem":"Packagist","name":"typo3/cms-backend","fixedVersion":"10.4.14"},{"ecosystem":"Packagist","name":"typo3/cms-backend","fixedVersion":"11.1.1"},{"ecosystem":"Packagist","name":"typo3/cms-core","fixedVersion":"10.4.14"},{"ecosystem":"Packagist","name":"typo3/cms-core","fixedVersion":"11.1.1"},{"ecosystem":"Packagist","name":"typo3/cms","fixedVersion":"10.4.14"},{"ecosystem":"Packagist","name":"typo3/cms","fixedVersion":"11.1.1"}],"fix":null,"references":[{"type":"ADVISORY","url":"https://github.com/TYPO3/TYPO3.CMS/security/advisories/GHSA-fjh3-g8gq-9q92"},{"type":"ADVISORY","url":"https://packagist.org/packages/typo3/cms-backend"},{"type":"ADVISORY","url":"https://typo3.org/security/advisory/typo3-core-sa-2021-007"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2021-21340"},{"type":"WEB","url":"https://github.com/FriendsOfPHP/security-advisories/blob/master/typo3/cms-core/CVE-2021-21340.yaml"},{"type":"WEB","url":"https://github.com/FriendsOfPHP/security-advisories/blob/master/typo3/cms/CVE-2021-21340.yaml"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-27T08:40:24.426974Z"}}