The vulnerability is a path traversal sanitization bypass in FUXA, allowing an authenticated administrator to craft nested traversal sequences to write files outside the intended directory. The attacker can place arbitrary scripts in runtime/script directories, and when the server reloads them, the malicious code executes with system privileges, leading to remote code execution.

Affected systems include all installations of frangoteam FUXA older than version 1.2.11. The flaw exists in the path sanitization logic used for file handling. Administrators with full access to the web interface can exploit it.

The CVSS score of 8.6 indicates high severity, while the EPSS score of less than 1% suggests low exploitation probability at present. The vulnerability is not listed in the KEV catalog. Exploitation requires authenticated administrative credentials, so limiting administrative access and applying the patch are critical. If the patch cannot be applied immediately, restricting write permissions to the vulnerable directories and monitoring for unauthorized file changes can mitigate risks.