{"id":"CVE-2026-19418","aliases":["EUVD-2026-55971","GHSA-4f2f-jr2m-j7p4","GHSA-68jx-f42c-7599"],"status":"published","title":"TYPO3 CMS - Broken Access Control in Backend and Install Tool","description":"The referrer enforcement introduced with TYPO3-CORE-SA-2020-006 (CVE-2020-11069) became ineffective in TYPO3 v13.0, where TYPO3 CMS started serving the backend and Install 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. This issue affects TYPO3 CMS versions 13.0.0-13.4.33 and 14.0.0-14.3.5.","severity":{"version":"4.0","score":7.3,"vector":"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","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.00242,"percentile":0.15449,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-346","CWE-352"],"published":"2026-08-11T07:29:37Z","modified":"2026-10-28T02:30:21Z","fixes":[{"ecosystem":"Packagist","package":"typo3/cms-backend","fixed_in":["13.4.34"],"sources":["ghsa","osv"]},{"ecosystem":"Packagist","package":"typo3/cms-core","fixed_in":["14.3.6"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"Packagist","package":"typo3/cms-backend","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"13.0.0"},{"fixed":"13.4.34"}]}]},{"source":"ghsa","ecosystem":"Packagist","package":"typo3/cms-core","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"14.0.0"},{"fixed":"14.3.6"}]}]},{"source":"osv","ecosystem":"Packagist","package":"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"]},{"source":"osv","ecosystem":"Packagist","package":"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"]}],"products":[{"vendor":"typo3","product":"typo3 cms"}],"references":[{"url":"https://typo3.org/security/advisory/typo3-core-sa-2026-021","tags":["vendor-advisory","advisory","web"]},{"url":"https://typo3.org/security/advisory/typo3-core-sa-2020-006","tags":["related","advisory","web"]},{"url":"https://github.com/TYPO3/typo3/commit/ae0abd329d52285fe6e92804c3608820ad45e872","tags":["patch","fix","web"]},{"url":"https://github.com/TYPO3/typo3/commit/a0e8ee06a40e959b9e7b06a4b1cb19d3a0d3dcf7","tags":["patch","fix","web"]},{"url":"https://github.com/TYPO3/typo3/commit/4a75e862c589c85d795d7c65dcdc835f8f413efc","tags":["patch","fix","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-19418","tags":["advisory"]},{"url":"https://github.com/FriendsOfPHP/security-advisories/blob/master/typo3/cms-core/CVE-2026-19418.yaml","tags":["web"]},{"url":"https://news.typo3.com/security/advisory/typo3-core-sa-2026-021","tags":["web"]},{"url":"https://github.com/advisories/GHSA-4f2f-jr2m-j7p4"},{"url":"https://github.com/TYPO3/typo3/security/advisories/GHSA-68jx-f42c-7599","tags":["web"]},{"url":"https://github.com/advisories/GHSA-68jx-f42c-7599"},{"url":"https://packagist.org","tags":["web"]},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/19xxx/CVE-2026-19418.json","tags":["advisory"]},{"url":"https://github.com/TYPO3/typo3","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2026-19418","title":"TYPO3 CMS - Broken Access Control in Backend and Install Tool","description":"The referrer enforcement introduced with TYPO3-CORE-SA-2020-006 (CVE-2020-11069) became ineffective in TYPO3 v13.0, where TYPO3 CMS started serving the backend and Install 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. This issue affects TYPO3 CMS versions 13.0.0-13.4.33 and 14.0.0-14.3.5.","status":"published","published":"2026-08-11T07:29:37.478Z","modified":"2026-08-11T13:21:08.298Z","cvss":[{"version":"4.0","score":7.3,"vector":"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","level":"high","assessor":"cna"}],"cwes":["CWE-346","CWE-352"],"updated_at":"2026-11-02T13:47:17.512524Z"}],"euvd":[{"id":"EUVD-2026-55971","description":"The referrer enforcement introduced with TYPO3-CORE-SA-2020-006 (CVE-2020-11069) became ineffective in TYPO3 v13.0, where TYPO3 CMS started serving the backend and Install 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. This issue affects TYPO3 CMS versions 13.0.0-13.4.33 and 14.0.0-14.3.5.","status":"published","published":"2026-08-11T07:29:37Z","modified":"2026-08-11T13:21:08Z","cvss":[{"version":"4.0","score":7.3,"vector":"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","level":"high"}],"updated_at":"2026-11-02T18:02:00.294626Z"}],"ghsa":[{"id":"GHSA-4f2f-jr2m-j7p4","title":"Duplicate Advisory: TYPO3-CORE-SA-2026-021: Broken Access Control in Backend and Install Tool","description":"## Duplicate Advisory\n\nThis advisory has been withdrawn because it is a duplicate of GHSA-68jx-f42c-7599. This link is maintained to preserve external references.\n\n## Original Description\nThe referrer enforcement introduced with TYPO3-CORE-SA-2020-006 (CVE-2020-11069) became ineffective in TYPO3 v13.0, where TYPO3 CMS started serving the backend and Install 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. This issue affects TYPO3 CMS versions 13.0.0-13.4.33 and 14.0.0-14.3.5.","status":"withdrawn","published":"2026-08-11T09:32:33Z","modified":"2026-09-01T21:30:53Z","cvss":[{"version":"4.0","score":7.3,"vector":"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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"high"}],"cwes":["CWE-346"],"updated_at":"2026-11-02T14:41:10.121131Z"},{"id":"GHSA-68jx-f42c-7599","title":"TYPO3 CMS - Broken Access Control in Backend and Install Tool","description":"### 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 \u0026 security team member Benjamin Franzke for fixing it.","status":"published","published":"2026-09-01T21:31:42Z","modified":"2026-09-01T21:31:43Z","cvss":[{"version":"4.0","score":7.3,"vector":"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","level":"high"}],"cwes":["CWE-346","CWE-352"],"updated_at":"2026-11-02T14:41:10.121131Z"}],"nvd":[{"id":"CVE-2026-19418","description":"The referrer enforcement introduced with TYPO3-CORE-SA-2020-006 (CVE-2020-11069) became ineffective in TYPO3 v13.0, where TYPO3 CMS started serving the backend and Install 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. This issue affects TYPO3 CMS versions 13.0.0-13.4.33 and 14.0.0-14.3.5.","status":"published","published":"2026-08-11T08:17:20.533Z","modified":"2026-10-23T19:10:00.167Z","cvss":[{"version":"4.0","score":7.3,"vector":"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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"high","assessor":"secondary"}],"cwes":["CWE-346","CWE-352"],"updated_at":"2026-11-02T14:12:36.102748Z"}],"osv":[{"id":"CVE-2026-19418","title":"TYPO3 CMS - Broken Access Control in Backend and Install Tool","description":"The referrer enforcement introduced with TYPO3-CORE-SA-2020-006 (CVE-2020-11069) became ineffective in TYPO3 v13.0, where TYPO3 CMS started serving the backend and Install 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. This issue affects TYPO3 CMS versions 13.0.0-13.4.33 and 14.0.0-14.3.5.","status":"published","published":"2026-08-11T07:29:37.478Z","modified":"2026-10-28T02:30:21.802910267Z","cvss":[{"version":"4.0","score":7.3,"vector":"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","level":"high"}],"cwes":["CWE-346","CWE-352"],"updated_at":"2026-11-02T15:44:58.024074Z"},{"id":"GHSA-4f2f-jr2m-j7p4","title":"Duplicate Advisory: TYPO3-CORE-SA-2026-021: Broken Access Control in Backend and Install Tool","description":"## Duplicate Advisory\n\nThis advisory has been withdrawn because it is a duplicate of GHSA-68jx-f42c-7599. This link is maintained to preserve external references.\n\n## Original Description\nThe referrer enforcement introduced with TYPO3-CORE-SA-2020-006 (CVE-2020-11069) became ineffective in TYPO3 v13.0, where TYPO3 CMS started serving the backend and Install 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. This issue affects TYPO3 CMS versions 13.0.0-13.4.33 and 14.0.0-14.3.5.","status":"withdrawn","published":"2026-08-11T09:32:33Z","modified":"2026-09-01T21:45:23.11243528Z","cvss":[{"version":"4.0","score":7.3,"vector":"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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"high"}],"cwes":["CWE-346"],"updated_at":"2026-11-02T15:46:36.782754Z"},{"id":"GHSA-68jx-f42c-7599","title":"TYPO3 CMS - Broken Access Control in Backend and Install Tool","description":"### 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 \u0026 security team member Benjamin Franzke for fixing it.","status":"published","published":"2026-09-01T21:31:42Z","modified":"2026-09-01T21:55:52.105169Z","cvss":[{"version":"4.0","score":7.3,"vector":"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","level":"high"}],"cwes":["CWE-346","CWE-352"],"updated_at":"2026-11-02T15:46:39.266402Z"}]}}