CVE-2026-85621 LobeChat 2.2.1 Webhook Signature Verification Bypass QQ Feishu
Unauthenticated attackers can bypass webhook signature verification in LobeChat to inject forged messages, impersonating trusted users to manipulate the AI agent.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-85621?
CVE-2026-85621 is a medium-severity authentication bypass vulnerability in lobehub, published on 4 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
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.
Weakness: CWE-345
Which versions are affected by CVE-2026-85621?
How do I fix CVE-2026-85621?
No fix has been published for CVE-2026-85621 yet. Limit exposure of the affected software until one is available.
Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.
Is CVE-2026-85621 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-85621 exists.
Sources
Also known as GHSA-627w-x4jq-g83v.