Vulnerability · Published Sep 4, 2026 · Assigned by ibm
CVE-2026-9138Langflow is vulnerable to arbitrary file write and arbitrary file deletion due to unvalidated paths in file-processing components
Medium 6.5
In plain English
A medium-severity path traversal in Langflow OSS from IBM. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 39% of all known vulnerabilities).
Official description
IBM Langflow OSS 1.0.0 through 1.11.2 Langflow could allow an authenticated attacker to write arbitrary files to the server due to improper input validation in the SaveToFileComponent. The application constructs local file paths using attacker‑controlled input without sufficient sanitization when handling requests to the /api/v1/run/{flow_id} endpoint. An attacker with low‑privileged authenticated access (such as a valid API key or user session) can supply crafted path values, including absolute paths or path traversal sequences, allowing arbitrary file writes to locations writable by the Langflow process. Successful exploitation may lead to unauthorized file creation or modification, potentially resulting in further compromise depending on the deployment environment.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| IBM | Langflow OSS | 1.0.0 – through 1.11.2 |
Weakness: CWE-22 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
References
- https://www.ibm.com/support/pages/node/7285643 vendor-advisory, patch