{"id":"CVE-2021-21358","aliases":["BIT-typo3-2021-21358","GHSA-x79j-wgqv-g8h2"],"url":"https://o3.security/vulnerability/CVE-2021-21358","summary":"Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') in typo3/cms-form","details":"\n### Problem\nIt has been discovered that the Form Designer backend module of the Form Framework is vulnerable to cross-site scripting. A valid backend user account with access to the form module is needed to exploit this vulnerability.\n\n### Solution\nUpdate to TYPO3 versions 10.4.14 or 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-2021-004](https://typo3.org/security/advisory/typo3-core-sa-2021-004)","published":"2021-03-23T02:15:12.813Z","modified":"2026-08-27T08:40:22.952229Z","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":0,"affectedPackages":[{"ecosystem":"Packagist","name":"typo3/cms-form","fixedVersion":"10.4.14"},{"ecosystem":"Packagist","name":"typo3/cms-form","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-x79j-wgqv-g8h2"},{"type":"ADVISORY","url":"https://packagist.org/packages/typo3/cms-form"},{"type":"ADVISORY","url":"https://typo3.org/security/advisory/typo3-core-sa-2021-004"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2021-21358"},{"type":"WEB","url":"https://github.com/FriendsOfPHP/security-advisories/blob/master/typo3/cms-core/CVE-2021-21358.yaml"},{"type":"WEB","url":"https://github.com/FriendsOfPHP/security-advisories/blob/master/typo3/cms/CVE-2021-21358.yaml"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-27T08:40:22.952229Z"}}