A flaw was found in the astralisone rive-mcp-server-core component where the libraryId argument supplied to importRiveFile.ts is not properly validated. By supplying malicious input, a local user can influence how the function constructs a file path, enabling traversal outside the intended directory. The weakness is a classic path traversal (CWE-22) and allows arbitrary read or write operations of files accessible to the application’s execution context.

All releases of astralisone:rive-mcp-server-core up to commit db1d0cc4cd52589116360428b7504fd0ca748b3e contain the vulnerable code. The project uses a rolling release scheme, so precise version numbers for patched releases are not yet published. Any deployment that includes the importRiveFile function is potentially affected.

The CVSS score of 4.8 indicates moderate severity. The EPSS score is not available, and the vulnerability is not included in CISA’s KEV catalog. Exploitation requires local access; an attacker with sufficient privileges on the host can choose arbitrary file paths and read or overwrite files if write permissions exist. No public exploits are known, but the lack of a vendor fix necessitates careful monitoring.