Mcp Server Fetch
Monthly
Server-side request forgery in the Model Context Protocol reference Fetch Tool (mcp-server-fetch, and the related mcp-server-everything) up to 2026.6.4 lets unauthenticated remote callers direct the fetch_url function at internal or otherwise restricted destinations by supplying a crafted url/path argument, with no destination validation in the default configuration. Impact is bounded but real: the assessed vector rates confidentiality and integrity impact as low with no availability impact, and the primary abuse case is reaching loopback services, private RFC1918 ranges, and cloud instance metadata endpoints (for example 169.254.169.254 and 100.100.100.100) from the server's network position rather than executing code. Publicly available exploit code exists (a public GitHub issue plus a VulDB entry) and the CVSS 4.0 vector carries an E:P proof-of-concept maturity flag, but there is no confirmed active exploitation (no CISA KEV listing); exposure depends on whether the Fetch Tool and its URL argument are reachable by an attacker, since these are reference servers frequently run locally beside an AI assistant.
Server-side request forgery in the Model Context Protocol reference Fetch Tool (mcp-server-fetch, and the related mcp-server-everything) up to 2026.6.4 lets unauthenticated remote callers direct the fetch_url function at internal or otherwise restricted destinations by supplying a crafted url/path argument, with no destination validation in the default configuration. Impact is bounded but real: the assessed vector rates confidentiality and integrity impact as low with no availability impact, and the primary abuse case is reaching loopback services, private RFC1918 ranges, and cloud instance metadata endpoints (for example 169.254.169.254 and 100.100.100.100) from the server's network position rather than executing code. Publicly available exploit code exists (a public GitHub issue plus a VulDB entry) and the CVSS 4.0 vector carries an E:P proof-of-concept maturity flag, but there is no confirmed active exploitation (no CISA KEV listing); exposure depends on whether the Fetch Tool and its URL argument are reachable by an attacker, since these are reference servers frequently run locally beside an AI assistant.