TYPO3 CMS - Broken Access Control in Backend and Install Tool
Summary
| CVE | CVE-2026-19418 |
|---|---|
| State | PUBLISHED |
| Assigner | TYPO3 |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-08-11 08:17:20 UTC |
| Updated | 2026-08-11 09:17:13 UTC |
| 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. |
Risk And Classification
Primary CVSS: v4.0 7.3 HIGH from f4fb688c-4412-4426-b4b8-421ecf27b14a
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
Problem Types: CWE-346 | CWE-352 | CWE-346 CWE-346 Origin Validation Error | CWE-352 CWE-352 Cross-Site Request Forgery (CSRF)
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 4.0 | f4fb688c-4412-4426-b4b8-421ecf27b14a | Secondary | 7.3 | HIGH | 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/C... |
| 4.0 | CNA | CVSS | 7.3 | HIGH | 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 |
CVSS v4.0 Breakdown
Attack Vector
NetworkAttack Complexity
LowAttack Requirements
PresentPrivileges Required
LowUser Interaction
ActiveConfidentiality
HighIntegrity
HighAvailability
HighSub Conf.
NoneSub Integrity
NoneSub Availability
NoneCVSS: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
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | TYPO3 | TYPO3 CMS | affected 13.0.0 13.4.34 semver | Not specified |
| CNA | TYPO3 | TYPO3 CMS | affected 14.0.0 14.3.6 semver | Not specified |
| CNA | TYPO3 | TYPO3 CMS | affected 13.0.0 13.4.34 semver | Not specified |
| CNA | TYPO3 | TYPO3 CMS | affected 14.0.0 14.3.6 semver | Not specified |
| CNA | TYPO3 | TYPO3 CMS | affected 14.0.0 14.3.6 semver | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| typo3.org/security/advisory/typo3-core-sa-2020-006 | f4fb688c-4412-4426-b4b8-421ecf27b14a | typo3.org | |
| github.com/TYPO3/typo3/commit/ae0abd329d52285fe6e92804c3608820ad45e872 | f4fb688c-4412-4426-b4b8-421ecf27b14a | github.com | |
| github.com/TYPO3/typo3/commit/a0e8ee06a40e959b9e7b06a4b1cb19d3a0d3dcf7 | f4fb688c-4412-4426-b4b8-421ecf27b14a | github.com | |
| github.com/TYPO3/typo3/commit/4a75e862c589c85d795d7c65dcdc835f8f413efc | f4fb688c-4412-4426-b4b8-421ecf27b14a | github.com | |
| typo3.org/security/advisory/typo3-core-sa-2026-021 | f4fb688c-4412-4426-b4b8-421ecf27b14a | typo3.org | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: Hổ Cao Từ (en)
CNA: Benjamin Franzke (en)
There are currently no legacy QID mappings associated with this CVE.