CVE-2026-85621: falha de média gravidade em lobehub

LobeChat (LobeHub) 2.2.1 does not properly verify inbound chat-platform webhook signatures in the QQ and Feishu adapters. The webhook route (/api/agent/webhooks/:platform) is unauthenticated by design and delegates verification to each adapter; the QQ adapter performs no Ed25519 signature verification on dispatched message events, and the Feishu adapter only performs an optional static-token comparison that is skipped when no token is configured (the default) and is not a body signature. An unauthenticated attacker who knows the public webhook URL can POST forged inbound messages with an attacker-chosen sender identity and arbitrary text, causing the bot owner's agent to process attacker-controlled input and treat the attacker as a trusted platform sender.