CVE-2026-102610

fast-agent can expose an unauthenticated agent on the network

fast-agent · fast-agent MCP server

First documented disclosure · Review checkpoint

Summary

Default network binding exposes the agent without authentication.

Severity and exploitation evidence

Medium · 6.4/10 · CVSS 3.1. Severity source.

Exploitation not established: The reviewed public sources describe the vulnerability and its conditions. Malicious exploitation has not been established in the reviewed sources.

Exploitation evidence source

Technical severity is not a measure of observed attacks or of risk to your deployment. Attempts, demonstrations, and successful compromise retain the qualifications in the source.

How the weakness works

The agent’s HTTP listener bound to all interfaces by default without authentication.

Conditions required

The MCP service must be network reachable. Host command execution additionally requires shell capability to be enabled.

Potential impact

Other network users can invoke exposed agent features with the service account’s access.

Affected versions and configurations

Before 0.7.21.

Fix and mitigation status

0.7.21.

Practical next steps

Upgrade to 0.7.21, verify the bind address and authenticate any intentional remote access.

Operating lesson

Default local tools to a local listener and make remote access an explicit decision.

Evidence and limits

The June 15 release change switched the default listener to loopback. Intentional remote deployments still require access control.

Sources