---
id: "CVE-2026-107366"
kind: "vulnerability"
aliases: ["CVE-2026-107366"]
title: "Langflow: message endpoints let any logged-in user alter others' messages"
severity: "high"
cvss: 8.3
epss: null
exploited: false
status: "open"
category: "ai-tooling"
products: []
ecosystems: []
tags: ["ai-apps", "ai-tooling", "langflow", "multi-user", "self-hosted"]
not_affected_if: ["single-user-instance", "version-outside-range"]
published_at: "2026-10-20T00:17:25+00:00"
first_seen_at: "2026-10-23T21:57:19+00:00"
updated_at: "2026-10-25T03:02:27+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-107366", "first_seen_at": "2026-10-23T21:57:19+00:00"}]
---

# Langflow: message endpoints let any logged-in user alter others' messages

Three message endpoints in IBM Langflow OSS 1.0.0 through 1.12.4 do not check who owns the messages they act on. An authenticated user can bulk-delete other users' messages, overwrite message content to inject prompts, or take over a conversation by reassigning its session ID.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Check the installed Langflow version with `langflow --version` or `pip show langflow`, and look for versions from `1.0.0` through `1.12.4`.
- Confirm whether multiple user accounts can reach the same Langflow instance.

## Fix

- Upgrade Langflow OSS to a release newer than `1.12.4`; the sources do not name the fixed version.
- Until patched, restrict Langflow access to trusted users only.

## Timeline

- 2026-10-23T21:57:19+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-107366

## From the sources

IBM Langflow OSS 1.0.0 through 1.12.4 contains three message endpoints that perform no ownership verification. Any authenticated user can bulk-delete another user's messages, overwrite message content to inject malicious prompts, or hijack an entire conversation session by reassigning its session ID.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_