Vulnerability · Published Oct 19, 2026 · Assigned by VulnCheck

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

Medium 6.5

In plain English

A medium-severity insufficient verification of data authenticity in LangBot from langbot-app. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 5% of all known vulnerabilities).

Severity (CVSS 3.1)6.5Medium

Exploit odds (30 days)0.2%top 95.4% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official 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.

Affected products (as reported)

Vendor	Product	Versions
langbot-app	LangBot	0 – through 4.11.0

Weakness: CWE-345 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:N

References

https://github.com/langbot-app/LangBot/issues/2627 issue-tracking
https://github.com/langbot-app/LangBot/commit/43c481d74a6388657b84baa7d292c613c75c24f9 patch
https://github.com/langbot-app/LangBot/blob/v4.11.0/src/langbot/pkg/platform/adapters/lark/adapter.py technical-description
https://github.com/langbot-app/LangBot/blob/v4.11.0/src/langbot/pkg/platform/sources/lark.py technical-description
https://github.com/langbot-app/LangBot/blob/v4.11.0/src/langbot/pkg/api/http/controller/groups/webhooks.py technical-description
VulnCheck Advisory: LangBot through 4.11.0 Missing Lark/Feishu Webhook Authenticity Verification third-party-advisory