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CVE-2026-33309

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

This page contains facts from public vulnerability sources. Check the original advisory before updating.

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.

CVSS 10.0 · Critical · EPSS 13.5% · Fix available

Published
Updated

Stack: python

Affected products and versions

  • langflow

    Versions
    • >= 1.2.0, < 1.9.0: Affected

    No fix published

  • langflow PyPI

    Versions
    • 1.2.0
    • 1.3.0
    • 1.3.1
    • 1.3.2
    • 1.3.3
    • 1.3.4
    • 1.4.0
    • 1.4.1
    • 1.4.2
    • 1.4.3
    • 1.5.0
    • 1.5.0.post1
    • 1.5.0.post2
    • 1.5.1
    • 1.6.0
    • 1.6.1
    • 1.6.2
    • 1.6.3
    • 1.6.4
    • 1.6.5
    • 1.6.6
    • 1.6.7
    • 1.6.8
    • 1.6.9
    • 1.7.0
    • 1.7.1
    • 1.7.2
    • 1.7.3
    • 1.8.0
    • 1.8.0rc0
    • 1.8.0rc1
    • 1.8.0rc2
    • 1.8.0rc3
    • 1.8.0rc4
    • 1.8.0rc5
    • 1.8.0rc6
    • 1.8.1
    • 1.8.2
    • 1.8.3
    • 1.8.3rc0
    • 1.8.4
    Affected ranges
    • ECOSYSTEM: ≥ 1.2.0, < 1.9.0

    Update to 1.9.0

Original sources

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