CVE-2026-53837

### Summary Mattermost handlers could fall open when channel type was missing. In affected versions, a Mattermost event missing channel type metadata could continue without applying the intended DM policy decision. 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 process a Mattermost event that should have been gated by channel policy. 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 `2026.5.6`. ### Mitigations keep Mattermost bot access restricted and review channel metadata errors 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.

### Summary Mattermost handlers could fall open when channel type was missing. In affected versions, a Mattermost event missing channel type metadata could continue without applying the intended DM policy decision. 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 process a Mattermost event that should have been gated by channel policy. 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 `2026.5.6`. ### Mitigations keep Mattermost bot access restricted and review channel metadata errors 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.

OpenClaw anterior a 2026.5.6 contiene una vulnerabilidad de control de acceso inadecuado en los manejadores de eventos de Mattermost que no valida los metadatos del tipo de canal. Los atacantes pueden eludir las decisiones de política de MD previstas enviando eventos de Mattermost manipulados que carecen de información del tipo de canal para procesar contenido restringido.