CVE-2026-112265

EUVD-2026-104308
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.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTPrimary
6.5 MEDIUM
NETWORK
HIGH
NONE
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:N
Awaiting analysis
This vulnerability is currently awaiting analysis.
Base Score
CVSS 3.x
EPSS Score
Percentile: 4.17%
Common Weakness Enumeration
References
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