CVE-2026-33309

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

State: Published
Severity: 10.0 Critical
Published: Mar 24, 2026
Updated: Mar 25, 2026
Reserved: Mar 18, 2026

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

CVSS	Score	Vector	Source
3.1	10.0 Critical	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H	GitHub_M

Weaknesses

CWE-22 Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
CWE-73 External Control of File Name or Path
CWE-94 Improper Control of Generation of Code ('Code Injection')
CWE-284 Improper Access Control

Affected Products

Product	Versions
langflowlangflow-ai	>= 1.2.0, < 1.9.0Affected

References

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

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