Executive brief
IBM Langflow OSS is a visual development platform for building AI applications. An authenticated attacker can bypass the security scanner's code execution restrictions due to an incomplete denylist, allowing them to execute arbitrary code on the server with the same privileges as the application process.
Technical details
The vulnerability exists in Langflow's agentic assistant code scanner, which uses an incomplete denylist to restrict dangerous operations. The scanner omits process-spawning primitives from its blocklist and contains a logic error where annotated class-body assignments bypass the safety check entirely. An authenticated attacker can craft a flow that uses these overlooked primitives to execute arbitrary code. The vulnerability requires prior authentication but no additional user interaction, and successful exploitation grants code execution at the application's privilege level.
Affected products
- IBM Langflow OSS 1.0.0 through 1.11.5
Timeline
- 2026-09-10: disclosed