The affected version of the LobeChat application, LobeHub 2.2.1, neglects to enforce cryptographic signature validation for messages received via the QQ and Feishu webhook adapters. The webhook endpoint is intentionally left unauthenticated; however, the adapter code fails to verify Ed25519 signatures or compare a configured static token. This omission allows any party that can reach the public webhook URL to forge inbound messages with a chosen sender identity and arbitrary content, causing the bot agent to treat the attacker as a genuine platform user and process the crafted input.

The vulnerability targets the LobeHub 2.2.1 release of the LobeChat platform, specifically the QQ and Feishu chat‑adapter modules that handle inbound webhook callbacks. No other product versions are listed in the CNA data.

The flaw has a CVSS score of 6.9, indicating moderate severity. The EPSS score is not available, and the issue is not listed in CISA KEV. An attacker only needs to know the public webhook URL; no authentication is required. By sending unauthenticated POST requests to the "/api/agent/webhooks/:platform" endpoint, the attacker can exploit the missing verification to inject counterfeit messages, potentially altering the behavior of the bot or executing commands on the agent machine.