CVE-2026-129094 · AI agents & MCP
NO FIX YET · SEE WHAT TO DO
The @utcp/http package before 1.1.14 fails to block loopback addresses when a {host} placeholder is used, so remote tool manuals can reach local services. An attacker can use host values like 127.0.0.1 or register tools through Streamable HTTP and SSE discovery to reach internal services on the machine running the agent.
first public May 10, 2026 · 1 source
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Teams running AI agents built on the UTCP HTTP client that load tool manuals from remote sources. Agents that only use locally defined tools or fixed, trusted endpoints are less exposed. unknown for any further detail the sources do not give.
Not affected if local-tools-only, trusted-endpoints-only
Who cares agents, mcp, node, utcp
@utcp/http in the project's lockfile or with npm ls @utcp/http{host} placeholder@utcp/http to 1.1.14 or later@utcp/http before 1.1.14 contains a server-side request forgery vulnerability that allows remote manuals to reach loopback services by bypassing the remote-loopback check with a {host} placeholder. Attackers can supply host arguments like 127.0.0.1 or register tools via Streamable HTTP and SSE discovery to access internal services on the agent machine.
This page as .md · .json · CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
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