The vulnerability resides in the is_safe_path function within the MCP File Handler component of 54yyyu code-mcp. It permits attackers to manipulate input paths so that the server resolves to files outside the intended directory, enabling unauthorized file access or potential remote code execution if executable files are accessed. The issue is exploitable remotely and has been publicly disclosed, which could compromise confidentiality, integrity, and availability of the affected system.

Any installation of 54yyyu code-mcp that incorporates version material up to and including commit 4cfc4643541a110c906d93635b391bf7e357f4a8 is vulnerable. The project uses a rolling release model and does not publish exact version release dates, so previous releases prior to this commit are likely affected.

The CVSS score is 6.9, indicating moderate severity. The EPSS score is not available and the vulnerability is not listed in CISA KEV, so there is currently no evidence of active exploitation. However, because the flaw can be triggered remotely via the server module and the repository is publicly available, the risk of exploitation remains moderate. Without an official fix, attackers could target exposed instances to read arbitrary files or run code if sufficient privileges are granted.