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. 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.
How to fix
- typo3/cms-backend13.4.34 or later
- typo3/cms-core14.3.6 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| typo3/cms-backendPackagist | 13.0.0 ≤ v < 13.4.34 | 13.4.34 |
| typo3/cms-corePackagist | 14.0.0 ≤ v < 14.3.6 | 14.3.6 |
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Attack Surface Management
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