CVE-2026-85621 json
LobeChat 2.2.1 Webhook Signature Verification Bypass QQ Feishu
published 2026-09-04 2 mo ago modified 2026-09-24 45 d ago also EUVD-2026-71228
- cvss
- 6.5
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.2%
- EPSS 0.2% chance of exploitation in 30 days, percentile 10%
- public exploits
- 0
- none known
Summary
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.
CISA SSVC
- Exploitation
- Proof of concept is public
- Automatable
- yes
- Technical impact
- partial
- Assessed
- 2 mo ago
Exploit prediction
0.20% chance of exploitation in the next 30 days, higher than 10% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- github.com https://github.com/lobehub/lobehub/issues/16538 referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 6.9 | 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 |
| CNA | 3.1 | 6.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N |
| CNA | 4.0 | 6.9 | 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
Affected products
- lobehub lobehub
Classification
- Weakness
-
- CWE-345 Insufficient Verification of Data Authenticity
References
-
github.com
/lobehub/lobehub/issues/16538
issue-tracking, exploit
-
github.com
/lobehub/lobehub
product
-
github.com
/lobehub/lobehub/blob/v2.2.15/packages/chat-adapter-qq/src/adapter.ts
technical-description
-
github.com
/lobehub/lobehub/blob/v2.2.15/packages/chat-adapter-feishu/src/adapter.ts
technical-description
-
vulncheck.com
/advisories/lobechat-2.2.1-webhook-signature-verification-bypass-qq-feishu
third-party-advisory
Sources
- CVE List CVE-2026-85621
- NVD CVE-2026-85621
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.