CVE-2026-33309CWE-22CWE-284CWE-73CWE-94

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

Critical · published March 24, 2026

CVSS v3.1
10.0
EPSS
1%
Percentile
65.1
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
10.0 · CRITICAL
Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
CVSS v4.0
Not supplied
EPSS
0.01089 · 65.1th percentile
Weaknesses
CWE-22 · Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal'); CWE-284 · Improper Access Control; CWE-73 · External Control of File Name or Path; CWE-94 · Improper Control of Generation of Code ('Code Injection')
Published
2026-03-24T12:49Z
EPSS history
Timeline
  • 25 SEP 03:25Z
    EPSS moved 11% → 1%
    epss
  • 24 MAR 12:49Z
    Langflow has an Arbitrary File Write (RCE) via v2 API
    cvelistv5