In microsandbox versions before 0.5.10, the runtime serializes secret network configuration values into command-line arguments and environment variables that are passed to sandboxed processes. These secrets are visible in the host's process table, including /proc command lines on Linux and process listings on Linux and macOS, for the lifetime of the sandbox process. This allows local users or other processes on the same host to read sensitive host-side API keys, tokens, and environment secrets without needing access to the sandbox or the spawning user's session. The vulnerability is addressed by changes introduced in version 0.5.10.

Exposure of sensitive host-side secrets such as API keys and tokens to local users or co-resident processes on shared hosts, continuous integration runners, and developer systems. This can lead to unauthorized disclosure of confidential information but does not allow direct code execution or modification of the sandbox environment.

Upgrade microsandbox to version 0.5.10 or later, where this issue is fixed. No other mitigation is required as the fix prevents sensitive information from being exposed in process arguments and environment variables.