IBM Langflow OSS versions 1.0.0 through 1.12.2 contain a flaw that allows an authenticated flow author to write attacker‑controlled content to any writable directory under the service account, bypassing the platform’s local file access isolation. An attacker can also craft an on‑disk index to read arbitrary files visible to the service process, including configuration secrets and database files. This is a classic path traversal vulnerability (CWE-22) that enables both write‑to‑arbitrary file and read‑of‑arbitrary file attacks.

The affected product is IBM Langflow OSS. Versions 1.0.0 through 1.12.2 are known to be vulnerable. The product was distributed through PyPI, with the CPEs indicating a range of deployments from v1.0.0 up to v1.12.2 under the IBM namespace.

The CVSS base score is 8.1, indicating a high‑severity vulnerability. EPSS data are not available, but the absence of a KEV listing suggests no widespread exploitation yet. The attack requires valid credentials of a flow author, so the risk is confined to environments where attackers can obtain or elevate such privileges. Once authenticated, an attacker can overwrite local configuration files or read sensitive data, potentially compromising application integrity and confidentiality.