CVE-2026-33309

Langflow has an Arbitrary File Write (RCE) via v2 API

Description

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.

Scores

Weaknesses (CWE)

• CWE-22
• CWE-73
• CWE-94
• CWE-284

Advisories

• GHSA-g2j9-7rj2-gm6c — Langflow has an Arbitrary File Write (RCE) via v2 API
• PYSEC-2026-79 — 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 (Exter

European references

• ENISA EUVD · EUVD-2026-14788
• GCVE · GCVE-0-2026-33309

Affected configurations (NVD CPE)

• cpe:2.3:a:langflow:langflow:*:*:*:*:*:*:*:* ≥ 1.2.0 < 1.9.0

Affected products

References

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

Sources