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Security Flaw in Langflow AI Tool Could Let Attackers Run Others' Workflows

A serious security weakness has been found in Langflow, a tool used to build AI-powered workflows. This flaw lets attackers run workflows belonging to other users if they have access to the system. The issue is actively being exploited, so it’s important for organisations using Langflow to update their software promptly.

09 July 2026

Reference: CVE-2026-55255

1. What is being reported?

The vulnerability is in Langflow versions before 1.9.1. It allows someone who is logged in to the system to run any AI workflow created by another user by simply using that user’s workflow ID. This means attackers can misuse or interfere with workflows they shouldn’t have access to. The problem has been fixed in version 1.9.1.

2. What this means in plain English

If your organisation uses Langflow, an attacker who gains access to your system could run AI workflows that belong to other users. This could lead to unauthorised actions or data misuse within your AI processes. Even if you don’t use Langflow directly, if your IT provider or cloud service uses it on your behalf, you could be at risk.

3. Could this affect a small business?

Small businesses or charities using Langflow for AI workflows could be affected, especially if they have multiple users or share access. Organisations not using Langflow or similar AI workflow tools are unlikely to be affected. Check with your software suppliers or IT provider if you are unsure.

4. What to do now

  • Check if your organisation uses Langflow and identify the version installed.
  • If using Langflow, update to version 1.9.1 or later as soon as possible.
  • If you use cloud services or third-party providers that use Langflow, ask them about their mitigation plans.
  • Review user access controls to limit who can run or manage AI workflows.

5. Ask your IT provider

Can you confirm if we use Langflow for AI workflows, and if so, have we updated to the secure version 1.9.1 or later to fix the known vulnerability CVE-2026-55255?

6. Bottom line

If you use Langflow, update it now to stop attackers from running workflows they shouldn’t have access to.

Information based on CISA KEV, NVD and reputable security reporting.

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