GHSA-qh2f-99mv-mrcf: OpenClaw: Bundle MCP loopback could miss its exec denylist on session spawn

The bundled MCP loopback is an entry point that carries an exec denylist, a list of commands it should not allow. On the session-spawn path in affected versions, that denylist was not applied. A caller who could reach this path started a session with wider command reach than the loopback should give. The weaknesses are listed as OS command injection (CWE-78) and improper access control (CWE-284). The advisory does not give the denylist entries or the tool names.

The CVSS 4.0 vector is network, low complexity, no privileges, no user interaction, with low impact on confidentiality, integrity and availability. The attacker must be able to reach the bundled MCP loopback. Commands run with the Gateway's rights. A prompt-injected agent that uses MCP tools could trigger the spawn path too.

The advisory leaves OpenClaw's trusted-operator model unchanged. The risk is in setups where lower-trust users or content can reach this path.

Affected: npm openclaw before 2026.5.12. You are exposed if the bundled MCP loopback is enabled and reachable by callers you do not fully trust.

npm ls -g openclaw

Drop -g for a project install. Check your Gateway configuration for the bundled MCP loopback.

Update to openclaw 2026.5.12, the first stable patched version.

npm install -g [email protected]

Until you can update, restrict bundled MCP loopback access to trusted operators. The advisory also suggests narrow channel and tool allowlists, not sharing one Gateway between mutually untrusted users, and disabling the feature if you do not need it.

The advisory gives no log line. Review sessions spawned through the bundled MCP loopback and the commands they ran. Compare those commands with your exec denylist, and look for ones it should have blocked. Check the process tree under the Gateway for unexpected shells or tools. Beam records agent shell commands and MCP tool calls, and its rules flag risky ones, which helps with this review.

Summary

Bundle MCP loopback could miss its exec denylist on session spawn. In affected versions, a caller that can reach the affected bundled MCP session-spawn path could bypass the denylist that was intended for that loopback MCP entry point.

This advisory is scoped to the named feature and configuration. It does not change OpenClaw's trusted-operator model: authenticated Gateway operators, installed plugins, and intentional local execution surfaces remain trusted unless a separate policy, approval, allowlist, sandbox, or auth boundary is crossed.

Impact

When the affected feature is enabled and reachable, this could start a session with broader command reach than that MCP path should provide. Practical impact depends on the operator's configuration and whether lower-trust input can reach that path.

Patched Versions

The first stable patched version is 2026.5.12.

Mitigations

restrict bundled MCP loopback access to trusted operators until patched. As general hardening, keep channel and tool allowlists narrow, avoid sharing one Gateway between mutually untrusted users, and disable the affected feature when it is not needed.