CVE-2026-9135 Policies Component Dynamic CodeInput Fields Bypass Custom Component Validation
Authenticated users can bypass custom component restrictions to execute arbitrary Python code via unvalidated dynamic fields in the Policies component.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-9135?
CVE-2026-9135 is a critical code injection vulnerability in Langflow Langflow, published on 17 Jul 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
IBM Langflow OSS 1.0.0 through 1.10.0 Langflow versions up to 1.9.2 (commit 94981c443d4918517b9e8163d70fc598dc33a32d) contain a code injection vulnerability in the Policies component's ToolGuard integration that bypasses the allow_custom_components=false security control. The vulnerability exists because the validation mechanism only checks the main component source code in node_template["code"]["value"] but fails to validate dynamic CodeInput fields that store generated ToolGuard Python files. Attackers can embed malicious Python code in these unvalidated dynamic fields, which are persisted in Flow.data and later executed server-side when a guarded tool is invoked through the ToolGuard runtime. This allows authenticated users with flow creation privileges to achieve arbitrary Python code execution on the backend despite custom component restrictions. The vulnerability can be escalated through cross-tenant flow manipulation via the agentic MCP update_flow_component_field tool, which accepts attacker-controlled user_id parameters, enabling attackers to inject malicious code into victim users' flows. When combined with publicly accessible flows and specific misconfigurations (AUTO_LOGIN=true, NEW_USER_IS_ACTIVE=true), the attack can be conducted with reduced authentication requirements.
Weakness: CWE-94
Which versions are affected by CVE-2026-9135?
It affects 1 product.
Products include Langflow Langflow.
How do I fix CVE-2026-9135?
No fix has been published for CVE-2026-9135 yet. Limit exposure of the affected software until one is available.
Upgrade, and never evaluate templates, expressions or code built from user input. More about Code injection.
Is CVE-2026-9135 being exploited?
There is no known exploitation of CVE-2026-9135 in the wild and no public exploit code.
Other vulnerabilities in Langflow Langflow
Sources
Also known as GHSA-mmph-9cw2-f8r6.