Vulnerability · Published Mar 24, 2026 · Assigned by GitHub_M

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

Critical 10.0

In plain English

A critical-severity path traversal in langflow from langflow-ai. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 13.5% (higher than 96% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)10.0Critical

Exploit odds (30 days)13.5%top 3.5% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official 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.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
PyPI	langflow	1.9.0	GHSA-g2j9-7rj2-gm6c
PyPI	langflow	1.9.0	PYSEC-2026-79

Affected products (as reported)

Vendor	Product	Versions
langflow-ai	langflow	>= 1.2.0, < 1.9.0

Weakness: CWE-22, CWE-73, CWE-94, CWE-284 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

References

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