Executive brief
IBM Langflow OSS is a visual workflow platform for building AI applications. An authenticated attacker can exploit a path traversal flaw in file handling to write files to arbitrary locations on the server, potentially overwriting critical system files, injecting malicious code, or corrupting application data. This impacts the confidentiality, integrity, and availability of systems running affected versions.
Technical details
The vulnerability is a path traversal (CWE-22) flaw in two independent file handling mechanisms within Langflow OSS. First, the file upload endpoint fails to sanitize the Content-Disposition filename field in multipart requests, allowing attackers to inject directory traversal sequences and write outside the intended storage boundary. Second, a file-writing workflow component accepts unsanitized user-controlled filenames without path containment enforcement. Both vectors require valid API authentication but no user interaction. A successful exploit allows arbitrary file write operations with the privileges of the server process. The fix is available in version 1.11.0.
Affected products
- IBM Langflow OSS 1.0.0 through 1.10.3
Timeline
- 2026-09-08: disclosed
- 2026-09-08: patched: Fix available in version 1.11.0