{"id":"CVE-2026-19418","aliases":["GHSA-68jx-f42c-7599"],"url":"https://o3.security/vulnerability/CVE-2026-19418","summary":"TYPO3 CMS - Broken Access Control in Backend and Install Tool","details":"### Problem\nThe referrer enforcement introduced with [TYPO3-CORE-SA-2020-006](https://news.typo3.com/security/advisory/typo3-core-sa-2020-006) ([CVE-2020-11069](https://www.cve.org/CVERecord?id=CVE-2020-11069)) became ineffective in TYPO3 v13.0, where TYPO3 CMS started serving the backend and Admin Tool applications from the site's main entry script instead of the dedicated typo3/ directory.\n\nWhether a request originated from the backend or Install Tool itself was determined by comparing the referrer against the directory of the entry script, which since then is the site root. As a consequence, requests originating from any script running on one of the TYPO3 instance's own domains, such as a frontend page, were accepted by backend routes and Install Tool endpoints.\n\nAttackers able to execute JavaScript on one of those domains, for instance by exploiting a cross-site scripting vulnerability, could invoke these endpoints via Fetch/XHR with the privileges of an authenticated victim's user session.\n\n### Solution\nUpdate to TYPO3 versions 13.4.34 LTS, 14.3.6 LTS that fix the problem described.\n\n### Credits\nThanks to Hổ Cao Từ for reporting this issue, and to TYPO3 core & security team member Benjamin Franzke for fixing it.","published":"2026-08-11T07:29:37.478Z","modified":"2026-09-01T21:55:52.105169984Z","cvss":null,"epss":{"score":0.00213,"percentile":0.11779,"asOf":"2026-09-17"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Packagist","name":"typo3/cms-backend","fixedVersion":"13.4.34"},{"ecosystem":"Packagist","name":"typo3/cms-core","fixedVersion":"14.3.6"}],"fix":{"url":"https://github.com/TYPO3/typo3/commit/4a75e862c589c85d795d7c65dcdc835f8f413efc","label":"TYPO3/typo3@4a75e86"},"references":[{"type":"WEB","url":"https://packagist.org"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/19xxx/CVE-2026-19418.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-19418"},{"type":"ADVISORY","url":"https://typo3.org/security/advisory/typo3-core-sa-2020-006"},{"type":"ADVISORY","url":"https://typo3.org/security/advisory/typo3-core-sa-2026-021"},{"type":"FIX","url":"https://github.com/TYPO3/typo3/commit/4a75e862c589c85d795d7c65dcdc835f8f413efc"},{"type":"FIX","url":"https://github.com/TYPO3/typo3/commit/a0e8ee06a40e959b9e7b06a4b1cb19d3a0d3dcf7"},{"type":"FIX","url":"https://github.com/TYPO3/typo3/commit/ae0abd329d52285fe6e92804c3608820ad45e872"},{"type":"PACKAGE","url":"https://github.com/TYPO3/typo3"},{"type":"WEB","url":"https://github.com/TYPO3/typo3/security/advisories/GHSA-68jx-f42c-7599"},{"type":"WEB","url":"https://github.com/FriendsOfPHP/security-advisories/blob/master/typo3/cms-core/CVE-2026-19418.yaml"},{"type":"WEB","url":"https://news.typo3.com/security/advisory/typo3-core-sa-2026-021"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-09-01T21:55:52.105169984Z"}}