Executive brief
OpenClaw, a gateway tool, contains a security flaw in how it handles Mattermost chat events. When certain metadata is missing from a message, the system may fail to apply security policies, potentially allowing restricted messages or actions to bypass intended filters. This could lead to unauthorized interactions within the chat environment depending on how the bot is configured.
Technical details
OpenClaw (npm package) is vulnerable to a 'fail open' condition (CWE-636) within its Mattermost event handlers. When a Mattermost event is received that lacks channel type metadata, the handler may proceed with processing without applying the required Direct Message (DM) policy or channel-based gating. This is a network-reachable vulnerability with high attack complexity, as it requires the absence of specific metadata to trigger the logic bypass. Exploitation allows an attacker to bypass channel-specific security policies. The issue is fixed in version 2026.5.6.
Affected products
- openclaw openclaw <= 2026.5.5
Timeline
- 2026-05-28: disclosed
- 2026-07-02: advisory
- 2026.5.6: patched