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.
Fix
Nothing published yet: no patch, vendor advisory or mitigation reference on NVD, no vendor advisory in the News for this CVE, not in CISA's KEV, no fixed package version. BaselineWatch does not guess at one.
Change history 1
- First seenCVSS 8.3NVD modified 2026-10-19 17:17
Affected (CPE criteria) 0
NVD has not attached CPE configurations yet.
References 6
- https://github.com/langbot-app/LangBot/blob/v4.11.0/src/langbot/pkg/api/http/controller/groups/webhooks.py
- 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/commit/43c481d74a6388657b84baa7d292c613c75c24f9
- https://github.com/langbot-app/LangBot/issues/2627
- https://www.vulncheck.com/advisories/langbot-through-4.11.0-missing-lark-feishu-webhook-authenticity-verification