CVE-2026-19418
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. 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.
INFO
Published Date :
Aug. 11, 2026, 8:17 a.m.
Last Modified :
Aug. 26, 2026, 5:13 p.m.
Remotely Exploit :
Yes !
Source :
f4fb688c-4412-4426-b4b8-421ecf27b14a
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 4.0 | HIGH | f4fb688c-4412-4426-b4b8-421ecf27b14a | ||||
| CVSS 4.0 | HIGH | f4fb688c-4412-4426-b4b8-421ecf27b14a |
Solution
- Upgrade TYPO3 CMS to a patched version.
- Ensure referrer enforcement is correctly configured.
- Apply security updates promptly.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-19418.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-19418 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-19418
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-19418 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-19418 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Aug. 11, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-19418', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-08-11T13:20:52.512047Z'} -
CVE Modified by f4fb688c-4412-4426-b4b8-421ecf27b14a
Aug. 11, 2026
Action Type Old Value New Value Changed Description The 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 ) 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. 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. -
New CVE Received by f4fb688c-4412-4426-b4b8-421ecf27b14a
Aug. 11, 2026
Action Type Old Value New Value Added Affected [{'repo': 'https://github.com/TYPO3/typo3', 'vendor': 'TYPO3', 'modules': ['Backend', 'Install'], 'product': 'TYPO3 CMS', 'versions': [{'status': 'affected', 'version': '13.0.0', 'lessThan': '13.4.34', 'versionType': 'semver'}, {'status': 'affected', 'version': '14.0.0', 'lessThan': '14.3.6', 'versionType': 'semver'}], 'packageName': 'typo3/cms-backend', 'collectionURL': 'https://packagist.org', 'defaultStatus': 'unaffected'}, {'repo': 'https://github.com/TYPO3/typo3', 'vendor': 'TYPO3', 'modules': ['Backend', 'Install'], 'product': 'TYPO3 CMS', 'versions': [{'status': 'affected', 'version': '13.0.0', 'lessThan': '13.4.34', 'versionType': 'semver'}, {'status': 'affected', 'version': '14.0.0', 'lessThan': '14.3.6', 'versionType': 'semver'}], 'packageName': 'typo3/cms-core', 'collectionURL': 'https://packagist.org', 'defaultStatus': 'unaffected'}, {'repo': 'https://github.com/TYPO3/typo3', 'vendor': 'TYPO3', 'modules': ['Backend', 'Install'], 'product': 'TYPO3 CMS', 'versions': [{'status': 'affected', 'version': '14.0.0', 'lessThan': '14.3.6', 'versionType': 'semver'}], 'packageName': 'typo3/cms-install', 'collectionURL': 'https://packagist.org', 'defaultStatus': 'unaffected'}] Added Description The 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 ) 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. Added CVSS V4.0 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 Added CWE CWE-352 Added CWE CWE-346 Added Reference https://github.com/TYPO3/typo3/commit/4a75e862c589c85d795d7c65dcdc835f8f413efc Added Reference https://github.com/TYPO3/typo3/commit/a0e8ee06a40e959b9e7b06a4b1cb19d3a0d3dcf7 Added Reference https://github.com/TYPO3/typo3/commit/ae0abd329d52285fe6e92804c3608820ad45e872 Added Reference https://typo3.org/security/advisory/typo3-core-sa-2020-006 Added Reference https://typo3.org/security/advisory/typo3-core-sa-2026-021