# CVE-2026-81211: IBM Langflow arbitrary code execution in custom components

Source: https://junglewise.ai/threats/cve-2026-81211-ibm-langflow-arbitrary-code-execution-in-custom-components  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-10. Updated: 2026-09-26  
License: CC BY 4.0 with a link back

CVE-2026-81211 · Severity: high · CVSS 8.8 · Published 2026-09-10

IBM Langflow is an open-source platform for building AI workflows. A vulnerability in the authorization controls for custom components in stored flows allows an authenticated attacker to execute arbitrary Python code on the server. An attacker could compromise the server, steal sensitive data, modify files, or move laterally within the network.

Technologies: [Langflow](https://junglewise.ai/threats/technologies/langflow). Vendors: [Langflow](https://junglewise.ai/threats/vendors/langflow).

## Quick answers

**Is CVE-2026-81211 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-81211 being exploited in the wild.

**How severe is CVE-2026-81211?** High severity, with a CVSS score of 8.8, published 10 September 2026.

**Which products and versions are affected?** IBM Langflow 1.0.0 through 1.11.5.

**Is there a fix for CVE-2026-81211?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-81211 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-81211?** Check whether you run Langflow. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

The vulnerability stems from improper authorization enforcement (CWE-862) of custom components in stored flows within Langflow OSS versions 1.0.0 through 1.11.5. The custom component admin-only policy is not enforced on the flow create and stored-flow build paths, only on the direct custom-component endpoint. An authenticated attacker can construct a flow containing attacker-controlled custom component source code and persist it, leading to arbitrary Python code execution with the privileges of the application process. Authentication is required to exploit this vulnerability; the attack vector is network-based.

## Affected products

- IBM Langflow 1.0.0 through 1.11.5

## Timeline

- 2026-09-10: disclosed

## References

- [https://www.ibm.com/support/pages/node/7286666](https://www.ibm.com/support/pages/node/7286666)

## Related threats

- [Langflow SSRF in URL-taking components](https://junglewise.ai/threats/langflow-ssrf-in-url-taking-components-protection-disabled-by-default-db7cac37)
- [Langflow authorization bypass in flow API endpoints](https://junglewise.ai/threats/cve-2026-105698-langflow-is-a-tool-for-building-and-deploying-ai-powered-agents)
- [Langflow MCP stdio command injection](https://junglewise.ai/threats/cve-2026-105697-langflow-is-a-tool-for-building-and-deploying-ai-powered-agents)
- [Langflow unsafe eval() in schema.py code execution](https://junglewise.ai/threats/cve-2026-101861-langflow-1-0-16-before-1-12-0-and-0-0-94-before-1-12-0-contain)
- [IBM Langflow OSS path traversal arbitrary file write](https://junglewise.ai/threats/cve-2026-84889-ibm-langflow-oss-path-traversal-arbitrary-file-write)