CVE-2026-53851: OpenClaw < 2026.5.12 - Slack Reaction Event Notification Bypass
Summary
Slack reaction events could ignore reaction notification settings. In affected versions, a Slack reaction event delivered to the configured app could enter the agent pipeline even when reaction notifications were disabled.
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 trigger unintended agent processing for reaction events. 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
disable or restrict Slack reaction event subscriptions until patched if this path is not needed. 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.
Other sources
OpenClaw before 2026.5.12 contains a notification bypass vulnerability allowing Slack reaction events to enter the agent pipeline despite disabled reaction notifications. Attackers can trigger unintended agent processing by sending reaction events when the feature is enabled, potentially leading to unauthorized processing of lower-trust input.
— MITRE
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
npm/openclawto a version that resolves this vulnerability.Fixed in 2026.5.12 - Configuration
Disable or restrict Slack reaction event subscriptions in OpenClaw until patched (update to 2026.5.12).
OpenClaw Slack integration Slack reaction event subscriptions = disabled or restricted - Compensating control
Keep channel and tool allowlists narrow (restrict which channels/tools can send events to OpenClaw).
- Compensating control
Avoid sharing one Gateway between mutually untrusted users (isolate Gateways to trusted operator groups).
Event History
Frequently Asked Questions
What is the severity of CVE-2026-53851?
The severity of CVE-2026-53851 is medium with a CVSS score of 6.3.
How do I fix CVE-2026-53851?
To fix CVE-2026-53851, upgrade to OpenClaw version 2026.5.12 or later.
What does CVE-2026-53851 affect?
CVE-2026-53851 affects Slack reaction event notifications in OpenClaw versions prior to 2026.5.12.
What is the impact of CVE-2026-53851?
The impact of CVE-2026-53851 can lead to unintended notification of Slack reactions even when configured settings are disabled.
Is CVE-2026-53851 related to specific software?
Yes, CVE-2026-53851 is specifically related to OpenClaw's implementation of Slack integration.