Advisory details:
github_osv / GHSA-4f2f-jr2m-j7p4
| Advisory ID | github_osv/GHSA-4f2f-jr2m-j7p4 |
| Aliases | |
| Summary | Duplicate Advisory: TYPO3-CORE-SA-2026-021: Broken Access Control in Backend and Install Tool ## Duplicate Advisory This advisory has been withdrawn because it is a duplicate of GHSA-68jx-f42c-7599. This link is maintained to preserve external references. ## Original 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. |
| Status | Published |
| Exploitability | 0.5 |
| Weighted Severity | 6.6 |
| Risk | 3.3 |
| Affected and Fixed Packages | Package Details |
| Introduced and Fixed Package Commit Patches | Package Commit Patches Details |
| CWE-346 | Origin Validation Error |
| System | Score | Found at |
|---|---|---|
| cvssv4 | 7.3 | https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/08/GHSA-4f2f-jr2m-j7p4/GHSA-4f2f-jr2m-j7p4.json |
| generic_textual | HIGH |
| Reference id | Reference type | URL |
|---|---|---|
| https://github.com/FriendsOfPHP/security-advisories/blob/master/typo3/cms-core/CVE-2026-19418.yaml | ||
| https://news.typo3.com/security/advisory/typo3-core-sa-2026-021 | ||
| https://typo3.org/security/advisory/typo3-core-sa-2020-006 | ||
| 4a75e862c589c85d795d7c65dcdc835f8f413efc | Other | https://github.com/TYPO3/typo3/commit/4a75e862c589c85d795d7c65dcdc835f8f413efc |
| a0e8ee06a40e959b9e7b06a4b1cb19d3a0d3dcf7 | Other | https://github.com/TYPO3/typo3/commit/a0e8ee06a40e959b9e7b06a4b1cb19d3a0d3dcf7 |
| ae0abd329d52285fe6e92804c3608820ad45e872 | Other | https://github.com/TYPO3/typo3/commit/ae0abd329d52285fe6e92804c3608820ad45e872 |
| CVE-2026-19418 | https://nvd.nist.gov/vuln/detail/CVE-2026-19418 | |
| typo3-core-sa-2026-021 | Advisory | https://typo3.org/security/advisory/typo3-core-sa-2026-021 |
No EPSS data available for this advisory.
| Patch URL | |
|---|---|
| There are no known patches. | |
| Attack Vector (AV) | Attack Complexity (AC) | Attack Requirements (AT) | Privileges Required (PR) | User Interaction (UI) | Vulnerable System Impact Confidentiality (VC) | Vulnerable System Impact Integrity (VI) | Vulnerable System Impact Availability (VA) | Subsequent System Impact Confidentiality (SC) | Subsequent System Impact Integrity (SI) | Subsequent System Impact Availability (SA) |
|---|---|---|---|---|---|---|---|---|---|---|
network adjacent local physical |
low high |
none present |
none low high |
none passive active |
high low none |
high low none |
high low none |
high low none |
high low none |
high low none |
There are no SSVC decisions available.