Missing Lark/Feishu webhook authenticity check in LangBot
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- High
- Attack requirements
- Present
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- Low · High · None
- Fix status
- No fix listed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-345.
Summary
LangBot through 4.11.0 is affected by a missing authenticity verification flaw, CWE-345, in its Lark/Feishu webhook handling. Unauthenticated remote attackers who know a bot UUID can send forged Lark/Feishu events because the signature checks are skipped. The forged events can drive the LLM pipeline, tools and approvals as other users.
Written with Claude Haiku 5.5 from the sources below · 2026-10-28
Description from the CNA
LangBot through 4.11.0 contains a missing authenticity verification vulnerability that allows unauthenticated attackers to inject forged Lark/Feishu events by skipping signature checks. Attackers knowing a bot UUID can POST fabricated im.message.receive_v1 or card.action.trigger events to drive the LLM pipeline, tools, and approvals as other users.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| langbot-app | LangBot | up to 4.11.0 | — | No fix listed | CNA |
- LangBot Vendorlangbot-app Affected up to 4.11.0 Fixed in — No fix listed CNA
Remediation
The sources list no fixed version for LangBot.
Written with Claude Haiku 5.5 from the sources below · 2026-10-28
Timeline
- 2026-10-19 Threatist record created from CVE-2026-112265
- 2026-10-19 Alias added: GHSA-73v9-9646-vcm5
References
Other 4
- https://github.com/langbot-app/LangBot/issues/2627
- https://github.com/langbot-app/LangBot/blob/v4.11.0/src/langbot/pkg/platform/adapters/lark/adapter.py
- https://github.com/langbot-app/LangBot/blob/v4.11.0/src/langbot/pkg/platform/sources/lark.py
- https://github.com/langbot-app/LangBot/blob/v4.11.0/src/langbot/pkg/api/http/controller/groups/webhooks.py
More langbot-app vulnerabilities
- TI-2026-61802 LangBot through 0.4.17 Unauthenticated Plugin Registration via WebSocket CVSS 4.0HIGH 8.8
- TI-2026-61576 LangBot before 4.10.11 Authentication Bypass via Weak Recovery Key CVSS 4.0CRITICAL 9.2
- TI-2025-37274 LangBot has a cross-directory file upload vulnerability, which could lead to system takeover CVSS 4.0HIGH 8.6
- TI-2026-39312 LangBot: Authenticated RCE Via MCP Configuration CVSS 3.1HIGH 8.8
Sources
- CVE-2026-112265 · CVE Program
- CVE-2026-112265 · NVD
- FIRST EPSS
- GHSA-73v9-9646-vcm5 · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences