Executive brief
IBM Langflow OSS, a visual interface for building AI workflows, contains a security flaw that allows users to access or modify files belonging to other users. By manipulating file paths, an authenticated attacker can steal sensitive data uploaded by others or overwrite their files with malicious information. This vulnerability breaks the privacy boundaries between different users on the same platform.
Technical details
An authorization bypass vulnerability (CWE-639) exists in the SaveToFile component of IBM Langflow OSS due to insufficient path ownership enforcement. An authenticated attacker can provide absolute file paths to target storage locations belonging to other users. When the component is used in 'append' mode, the attacker can read victim file contents by appending data and viewing the resulting output in their own namespace. In 'overwrite' mode, the attacker can replace victim files with arbitrary data. The vulnerability is reachable over the network and requires low-privileged authentication. It has been addressed in version 1.10.2.
Affected products
- IBM Langflow OSS 1.0.0 through 1.10.1
Timeline
- 2026-07-14: advisory: Initial publication by IBM
- 2026-07-17: disclosed: NVD publication date
- 2026-07-14: patched: Version 1.10.2 released to address the issue