CVE-2026-33309 — Langflow has an Arbitrary File Write (RCE) via v2 API

Description (CNA)

Langflow is a tool for building and deploying AI-powered agents and workflows. Versions 1.2.0 through 1.8.1 have a bypass of the patch for CVE-2025-68478 (External Control of File Name), leading to the root architectural issue within `LocalStorageService` remaining unresolved. Because the underlying storage layer lacks boundary containment checks, the system relies entirely on the HTTP-layer `ValidatedFileName` dependency. This defense-in-depth failure leaves the `POST /api/v2/files/` endpoint vulnerable to Arbitrary File Write. The multipart upload filename bypasses the path-parameter guard, allowing authenticated attackers to write files anywhere on the host system, leading to Remote Code Execution (RCE). Version 1.9.0 contains an updated fix.

Affected (CNA)

Vendor / product	Versions
langflow-ai / langflow	affected >= 1.2.0, < 1.9.0

CWE

CWE-22, CWE-73, CWE-94, CWE-284

References

https://github.com/langflow-ai/langflow/security/advisories/GHSA-g2j9-7rj2-gm6c

ADP enrichment

CISA-ADP

No English description supplied.

No references supplied.