The vulnerability is a path traversal flaw in the finetune Gradio handlers of F5‑TTS. Unsanitized project names are passed directly to os.path.join without ensuring that the resolved path remains inside the intended base directory. An attacker can provide an absolute path such as /tmp/EVIL, which causes the application to create arbitrary directories and files wherever the server process has write permission. By writing attacker‑controlled JSON content or other files, the attacker could overwrite critical configuration files, inject malicious code, or facilitate further compromise of the server.

This issue affects the F5‑TTS application from SWivid, specifically version 1.1.20 and earlier. The path traversal flaw can be exploited through the finetune Gradio endpoint exposed by these versions.

With a CVSS score of 8.8, the vulnerability is classified as high severity. The EPSS score is not available, and the vulnerability is not listed in the CISA KEV catalog. Attackers can exploit it without authentication via the publicly accessible finetune Gradio interface. The flaw allows writing arbitrary files to any location writable by the server process, which can compromise configuration integrity and system stability. If these files are later executed or parsed by the application or other services, code execution could occur, but that outcome is inferred from the description and not explicitly confirmed.