{"id":"CVE-2026-19418","state":"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.","publishedAt":"2026-08-11T07:29:37.478Z","updatedAt":"2026-08-11T13:21:08.298Z","severity":{"score":7.3,"label":"High","version":"4.0","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","source":"TYPO3"},"assigner":"TYPO3","products":["TYPO3 TYPO3 CMS"],"affected":[{"vendor":"TYPO3","product":"TYPO3 CMS","packageName":"typo3/cms-backend","defaultStatus":"unaffected","versions":[{"version":"13.0.0","status":"affected","lessThan":"13.4.34","versionType":"semver"},{"version":"14.0.0","status":"affected","lessThan":"14.3.6","versionType":"semver"}],"collectionURL":"https://packagist.org","repo":"https://github.com/TYPO3/typo3","modules":["Backend","Install"]},{"vendor":"TYPO3","product":"TYPO3 CMS","packageName":"typo3/cms-core","defaultStatus":"unaffected","versions":[{"version":"13.0.0","status":"affected","lessThan":"13.4.34","versionType":"semver"},{"version":"14.0.0","status":"affected","lessThan":"14.3.6","versionType":"semver"}],"collectionURL":"https://packagist.org","repo":"https://github.com/TYPO3/typo3","modules":["Backend","Install"]},{"vendor":"TYPO3","product":"TYPO3 CMS","packageName":"typo3/cms-install","defaultStatus":"unaffected","versions":[{"version":"14.0.0","status":"affected","lessThan":"14.3.6","versionType":"semver"}],"collectionURL":"https://packagist.org","repo":"https://github.com/TYPO3/typo3","modules":["Backend","Install"]}],"references":["https://typo3.org/security/advisory/typo3-core-sa-2026-021","https://typo3.org/security/advisory/typo3-core-sa-2020-006","https://github.com/TYPO3/typo3/commit/ae0abd329d52285fe6e92804c3608820ad45e872","https://github.com/TYPO3/typo3/commit/a0e8ee06a40e959b9e7b06a4b1cb19d3a0d3dcf7","https://github.com/TYPO3/typo3/commit/4a75e862c589c85d795d7c65dcdc835f8f413efc"],"weaknesses":["CWE-346","CWE-352"],"ingestedAt":"2026-10-29T20:11:10.572Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/19xxx/CVE-2026-19418.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-19418","state":"PUBLISHED","datePublished":"2026-08-11T07:29:37.478Z","dateUpdated":"2026-08-11T13:21:08.298Z","assignerShortName":"TYPO3","assignerOrgId":"f4fb688c-4412-4426-b4b8-421ecf27b14a","dateReserved":"2026-08-10T10:44:33.352Z"},"containers":{"cna":{"title":"TYPO3 CMS - Broken Access Control in Backend and Install Tool","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"TYPO3","product":"TYPO3 CMS","packageName":"typo3/cms-backend","defaultStatus":"unaffected","versions":[{"version":"13.0.0","status":"affected","lessThan":"13.4.34","versionType":"semver"},{"version":"14.0.0","status":"affected","lessThan":"14.3.6","versionType":"semver"}],"collectionURL":"https://packagist.org","repo":"https://github.com/TYPO3/typo3","modules":["Backend","Install"]},{"vendor":"TYPO3","product":"TYPO3 CMS","packageName":"typo3/cms-core","defaultStatus":"unaffected","versions":[{"version":"13.0.0","status":"affected","lessThan":"13.4.34","versionType":"semver"},{"version":"14.0.0","status":"affected","lessThan":"14.3.6","versionType":"semver"}],"collectionURL":"https://packagist.org","repo":"https://github.com/TYPO3/typo3","modules":["Backend","Install"]},{"vendor":"TYPO3","product":"TYPO3 CMS","packageName":"typo3/cms-install","defaultStatus":"unaffected","versions":[{"version":"14.0.0","status":"affected","lessThan":"14.3.6","versionType":"semver"}],"collectionURL":"https://packagist.org","repo":"https://github.com/TYPO3/typo3","modules":["Backend","Install"]}],"references":[{"url":"https://typo3.org/security/advisory/typo3-core-sa-2026-021","tags":["vendor-advisory"]},{"url":"https://typo3.org/security/advisory/typo3-core-sa-2020-006","name":"TYPO3-CORE-SA-2020-006 (previous fix of the same protection mechanism)","tags":["related"]},{"url":"https://github.com/TYPO3/typo3/commit/ae0abd329d52285fe6e92804c3608820ad45e872","name":"Git commit of main branch","tags":["patch"]},{"url":"https://github.com/TYPO3/typo3/commit/a0e8ee06a40e959b9e7b06a4b1cb19d3a0d3dcf7","name":"Git commit of 14.3 branch","tags":["patch"]},{"url":"https://github.com/TYPO3/typo3/commit/4a75e862c589c85d795d7c65dcdc835f8f413efc","name":"Git commit of 13.4 branch","tags":["patch"]}],"metrics":[{"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}],"cvssV4_0":{"attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"PRESENT","privilegesRequired":"LOW","userInteraction":"ACTIVE","vulnConfidentialityImpact":"HIGH","subConfidentialityImpact":"NONE","vulnIntegrityImpact":"HIGH","subIntegrityImpact":"NONE","vulnAvailabilityImpact":"HIGH","subAvailabilityImpact":"NONE","exploitMaturity":"NOT_DEFINED","Safety":"NOT_DEFINED","Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","valueDensity":"NOT_DEFINED","vulnerabilityResponseEffort":"NOT_DEFINED","providerUrgency":"NOT_DEFINED","version":"4.0","baseSeverity":"HIGH","baseScore":7.3,"vectorString":"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"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-346","lang":"en","description":"CWE-346 Origin Validation Error","type":"CWE"},{"cweId":"CWE-352","lang":"en","description":"CWE-352 Cross-Site Request Forgery (CSRF)","type":"CWE"}]}],"providerMetadata":{"shortName":"TYPO3","orgId":"f4fb688c-4412-4426-b4b8-421ecf27b14a","dateUpdated":"2026-08-11T08:05:01.460Z"},"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:a:typo3:typo3:*:*:*:*:*:*:*:*","versionEndExcluding":"13.4.34","versionStartIncluding":"13.0.0","vulnerable":true},{"criteria":"cpe:2.3:a:typo3:typo3:*:*:*:*:*:*:*:*","versionEndExcluding":"14.3.6","versionStartIncluding":"14.0.0","vulnerable":true}],"negate":false,"operator":"OR"}],"operator":"OR"}],"credits":[{"lang":"en","value":"Hổ Cao Từ","type":"reporter"},{"lang":"en","value":"Benjamin Franzke","type":"remediation developer"}],"source":{"discovery":"UNKNOWN"},"x_generator":{"engine":"Vulnogram 1.0.1"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-08-11T13:20:52.512047Z","id":"CVE-2026-19418","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-08-11T13:21:08.298Z"}}]}}}