CVE-2026-50143

Name of the Vulnerable Software and Affected Versions @apify/actors-mcp-server versions prior to 0.10.11

Description An authority injection issue exists where the software constructs Actor standby URLs by concatenating a trusted base URL with an attacker-controlled webServerMcpPath variable without proper validation. A malicious Actor publisher can use a userinfo-style value (containing an @ character) in the webServerMcpPath to redirect the MCP client to a third-party host. Because the client unconditionally attaches the victim's Authorization bearer token to outbound connections, the Apify API token is exfiltrated to the attacker's server. This allows unauthorized access to the victim's account, including Actors, stored data, and billable compute. The issue is triggered when a victim invokes or inspects a malicious Actor via the call-actor or fetch-actor-details tools, or during actor-mcp type tool loading. The vulnerable function is getActorMCPServerURL() located in src/mcp/actors.ts.

Recommendations Update to version 0.10.11. As a temporary mitigation, avoid invoking or inspecting Actors from untrusted publishers.