{"id":"GHSA-68jx-f42c-7599","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.","aliases":["CVE-2026-19418"],"modified":"2026-09-01T21:55:52.105169Z","published":"2026-09-01T21:31:42Z","database_specific":{"cwe_ids":["CWE-346","CWE-352"],"severity":"HIGH","github_reviewed":true,"github_reviewed_at":"2026-09-01T21:31:42Z","nvd_published_at":null},"references":[{"type":"WEB","url":"https://github.com/TYPO3/typo3/security/advisories/GHSA-68jx-f42c-7599"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-19418"},{"type":"WEB","url":"https://github.com/TYPO3/typo3/commit/4a75e862c589c85d795d7c65dcdc835f8f413efc"},{"type":"WEB","url":"https://github.com/TYPO3/typo3/commit/a0e8ee06a40e959b9e7b06a4b1cb19d3a0d3dcf7"},{"type":"WEB","url":"https://github.com/TYPO3/typo3/commit/ae0abd329d52285fe6e92804c3608820ad45e872"},{"type":"WEB","url":"https://github.com/FriendsOfPHP/security-advisories/blob/master/typo3/cms-core/CVE-2026-19418.yaml"},{"type":"PACKAGE","url":"https://github.com/TYPO3/typo3"},{"type":"WEB","url":"https://news.typo3.com/security/advisory/typo3-core-sa-2026-021"},{"type":"WEB","url":"https://typo3.org/security/advisory/typo3-core-sa-2020-006"},{"type":"WEB","url":"https://typo3.org/security/advisory/typo3-core-sa-2026-021"}],"affected":[{"package":{"name":"typo3/cms-backend","ecosystem":"Packagist","purl":"pkg:composer/typo3/cms-backend"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"13.0.0"},{"fixed":"13.4.34"}]}],"versions":["v13.0.0","v13.0.1","v13.1.0","v13.1.1","v13.2.1","v13.3.0","v13.3.1","v13.4.0","v13.4.1","v13.4.10","v13.4.11","v13.4.12","v13.4.13","v13.4.14","v13.4.15","v13.4.16","v13.4.17","v13.4.18","v13.4.19","v13.4.2","v13.4.20","v13.4.21","v13.4.22","v13.4.23","v13.4.24","v13.4.25","v13.4.26","v13.4.27","v13.4.28","v13.4.29","v13.4.3","v13.4.30","v13.4.31","v13.4.32","v13.4.33","v13.4.4","v13.4.5","v13.4.6","v13.4.7","v13.4.8","v13.4.9"],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/09/GHSA-68jx-f42c-7599/GHSA-68jx-f42c-7599.json"}},{"package":{"name":"typo3/cms-core","ecosystem":"Packagist","purl":"pkg:composer/typo3/cms-core"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"14.0.0"},{"fixed":"14.3.6"}]}],"versions":["v14.0.0","v14.0.1","v14.0.2","v14.1.0","v14.1.1","v14.2.0","v14.3.0","v14.3.1","v14.3.2","v14.3.3","v14.3.4","v14.3.5"],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/09/GHSA-68jx-f42c-7599/GHSA-68jx-f42c-7599.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N"}]}