CVE-2026-47343: TYPO3 CMS - Destructive Actions on File Mount Folders

Synopsis

An authorization bypass in TYPO3 CMS allows non-privileged backend users with file mount access to perform destructive write operations, including moving, deleting, and renaming folders that serve as the root of an active file mount. The vulnerability is reachable over the network and requires only a low-privilege backend account with no additional interaction from other users. Successful exploitation lets an attacker tamper with or destroy file mount structures, disrupting access to files across the application. Patched-image rebuilds at versions 10.4.57, 11.5.51, 12.4.46, 13.4.31, and 14.3.3 are available on HarborGuard for environments running an affected version.

HarborGuard Coverage

Exploit Conditions

• Network reachabilityRequired

  The vulnerable endpoint is exposed over the network, so an attacker must be able to reach the TYPO3 backend via HTTP/HTTPS.

• AuthenticationRequired

  A valid TYPO3 backend account with file mount access is needed, though any low-privilege account with that access is sufficient.

• Victim interactionNot required

  The attacker can perform the destructive file mount operations entirely on their own, with no action required from another user.

• Attack complexityDetail

  Exploitation is reliable and condition-free; no race conditions, specific memory layout, or unusual environmental factors are required.

Blast Radius

• An attacker can delete the root folder of any file mount they have access to, permanently destroying stored files and making the mount unavailable to all users.
• An attacker can rename or move file mount root folders, breaking application references to those paths and disrupting content delivery or backend workflows that depend on them.
• Integrity of the file system structure within affected mounts is compromised, which may cause cascading errors in TYPO3 pages or extensions that rely on those file resources.
• Availability of file-dependent content is degraded for the duration that the mount root remains missing or mislocated.