TYPO3 Mask up to 8.3.11/9.0.10 Mask module template element key path traversal

Summaryinfo

A vulnerability classified as critical was found in TYPO3 Mask up to 8.3.11/9.0.10. Impacted is an unknown function of the component Mask module. Such manipulation of the argument template element key leads to path traversal. This vulnerability is uniquely identified as CVE-2026-77139. The attack can be launched remotely. No exploit exists.

Detailsinfo

A vulnerability was found in TYPO3 Mask up to 8.3.11/9.0.10. It has been rated as critical. Affected by this issue is an unknown function of the component Mask module. The manipulation of the argument template element key with an unknown input leads to a path traversal vulnerability. Using CWE to declare the problem leads to CWE-22. The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory. Impacted is confidentiality, integrity, and availability. CVE summarizes:

The extension fails to validate a client-supplied template element key before using it to build file paths for saving and deleting Mask template files. An authenticated backend user with access to the Mask module can supply a key containing path traversal sequences to create or delete .html files outside the configured template directory.

The advisory is available at typo3.org. This vulnerability is handled as CVE-2026-77139 since 08/20/2026. The exploitation is known to be easy. The attack may be launched remotely. Technical details are known, but there is no available exploit. This vulnerability is assigned to T1006 by the MITRE ATT&CK project.

Upgrading to version 8.3.12 or 9.0.11 eliminates this vulnerability.

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Productinfo

Type

• Content Management System

Vendor

• TYPO3

Name

• Mask

Version

• 8.3.0
• 8.3.1
• 8.3.2
• 8.3.3
• 8.3.4
• 8.3.5
• 8.3.6
• 8.3.7
• 8.3.8
• 8.3.9
• 8.3.10
• 8.3.11
• 9.0.0
• 9.0.1
• 9.0.2
• 9.0.3
• 9.0.4
• 9.0.5
• 9.0.6
• 9.0.7
• 9.0.8
• 9.0.9
• 9.0.10

License

• open-source

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

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