OpenClaw: Slack thread context could include messages from non-allowlisted senders

Summary

Before OpenClaw 2026.4.2, Slack thread starter and thread-history context fetched through the API was not filtered by the effective sender allowlist. Messages from non-allowlisted senders could still enter the agent context when an allowlisted user replied in the same thread.

Impact

A Slack deployment that relied on sender allowlists could still feed non-allowlisted thread content into the model context through thread history. This was a sender-access-control bypass on Slack thread context, not a direct channel-auth bypass.

Affected Packages / Versions

• Package: openclaw (npm)
• Affected versions: <= 2026.4.1
• Patched versions: >= 2026.4.2
• Latest published npm version: 2026.4.1

Fix Commit(s)

• ac5bc4fb37becc64a2ec314864cca1565e921f2d — filter Slack thread context by the effective allowlist

Release Process Note

The fix is present on main and is staged for OpenClaw 2026.4.2. Publish this advisory after the 2026.4.2 npm release is live.

OpenClaw thanks @AntAISecurityLab for reporting.