Vulnerability 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. Whether 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. Attackers 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.
Related Weaknesses (CWE)
References
- https://github.com/TYPO3/typo3/commit/4a75e862c589c85d795d7c65dcdc835f8f413efc
- https://github.com/TYPO3/typo3/commit/a0e8ee06a40e959b9e7b06a4b1cb19d3a0d3dcf7
- https://github.com/TYPO3/typo3/commit/ae0abd329d52285fe6e92804c3608820ad45e872
- https://typo3.org/security/advisory/typo3-core-sa-2020-006
- https://typo3.org/security/advisory/typo3-core-sa-2026-021
FAQ
What is CVE-2026-19418?
CVE-2026-19418 is a documented vulnerability. 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 s...
How severe is CVE-2026-19418?
CVSS scoring is not yet available for CVE-2026-19418. Check NVD for updates.
Is there a patch for CVE-2026-19418?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.