CVE-2026-85621 Details

A vulnerability exists in LobeChat (LobeHub) version 2.2.1, where the application fails to properly verify webhook signatures for incoming messages in the QQ and Feishu chat platform adapters. The webhook route is intentionally left unauthenticated and relies on each adapter to perform signature verification. However, the QQ adapter does not implement any signature verification for dispatched message events, while the Feishu adapter only conducts an optional static-token comparison that is bypassed if no token is configured (which is the default) and does not verify the request body signature even when a token is set. This flaw allows an unauthenticated attacker, aware of the public webhook URL, to send forged messages with a spoofed sender identity and arbitrary content. The recipient's bot processes this attacker-controlled input as if it were a trusted platform message, effectively injecting prompts into the conversation.

To address this vulnerability, implement proper signature verification for incoming webhooks in both the QQ and Feishu adapters. For QQ, verify the Ed25519 signature using the client secret, and for Feishu, compute and verify the Lark request signature over the raw body, making verification mandatory rather than optional.