Langflow Validate Code Endpoint Dangerous Python Execution Indicators - STRICT
SIGMA detection rule by Adama ASSIONGBON (SOC & CTI Consultant), https://linkedin.com/in/adama-assiongbon-9029893a · Unknown
Detects high confidence CVE-2026-9198 exploitation when the Langflow validate/code endpoint receives Python source containing dangerous execution, network, or credential harvesting primitives. SOC L1 should verify the source, affected host, user, process or request fields, timing, and related activity.
Detecte les tentatives haute confiance d'exploitation CVE-2026-9198 lorsque l'endpoint /api/v1/validate/code de Langflow recoit un corps JSON avec un champ code contenant des primitives Python dangereuses comme subprocess, os.system, os.popen, socket, pty.spawn, base64/b64decode combine a exec ou eval, ou une tentative de lecture de secrets runtime (/proc/self/environ, OPENAI_API_KEY, DATABASE_URL). Cet endpoint est concu pour valider la syntaxe d'un composant, pas pour produire un effet de bord systeme : la presence de ces primitives dans un appel de validation est en soi un signal fort de compromission, independamment de la maniere dont l'attaquant a obtenu l'acces (chaine auto_login ou session volee). Le SOC L1 doit vérifier la source, l’hôte affecté, l’utilisateur, les champs de processus ou de requête, la chronologie et les activités associées.
title: Langflow Validate Code Endpoint Dangerous Python Execution Indicators - STRICT
id: 124cd7ff-ef60-4730-aa10-21af09efb4d5
status: experimental
description: |
Detects high confidence CVE-2026-9198 exploitation when the Langflow validate/code endpoint receives Python source containing dangerous execution, network, or credential harvesting primitives. SOC L1 should verify the source, affected host, user, process or request fields, timing, and related activity.
Detecte les tentatives haute confiance d'exploitation CVE-2026-9198 lorsque l'endpoint /api/v1/validate/code de Langflow recoit un corps JSON avec un champ code contenant des primitives Python dangereuses comme subprocess, os.system, os.popen, socket, pty.spawn, base64/b64decode combine a exec ou eval, ou une tentative de lecture de secrets runtime (/proc/self/environ, OPENAI_API_KEY, DATABASE_URL). Cet endpoint est concu pour valider la syntaxe d'un composant, pas pour produire un effet de bord systeme : la presence de ces primitives dans un appel de validation est en soi un signal fort de compromission, independamment de la maniere dont l'attaquant a obtenu l'acces (chaine auto_login ou session volee). Le SOC L1 doit vérifier la source, l’hôte affecté, l’utilisateur, les champs de processus ou de requête, la chronologie et les activités associées.
references:
- https://nvd.nist.gov/vuln/detail/CVE-2026-9198
- https://www.ibm.com/support/pages/node/7278927
- https://www.sentinelone.com/vulnerability-database/cve-2026-9198/
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-9198
- https://thehackernews.com/2026/08/cisa-flags-langflow-rce-tomcat-and-n.html
author: Adama ASSIONGBON (SOC & CTI Consultant), https://linkedin.com/in/adama-assiongbon-9029893a
date: 2026-08-05
related:
- id: 56652eed-81a4-4a47-bd93-e906ce5440c7
type: derived
logsource:
category: webserver
detection:
selection_endpoint_cs_uri_stem:
cs-uri-stem|contains: '/api/v1/validate/code'
selection_endpoint_uri:
Uri|contains: '/api/v1/validate/code'
selection_endpoint_url:
Url|contains: '/api/v1/validate/code'
selection_endpoint_url_path:
url.path|contains: '/api/v1/validate/code'
selection_endpoint_request_uri:
request_uri|contains: '/api/v1/validate/code'
selection_http_post_cs_method:
cs-method:
- 'POST'
- 'post'
selection_http_post_http_method:
HttpMethod:
- 'POST'
- 'post'
selection_http_post_method:
http.request.method:
- 'POST'
- 'post'
selection_code_field_requestbody:
RequestBody|contains: '"code"'
selection_code_field_http_body:
http.request.body.content|contains: '"code"'
selection_code_field_postdata:
post_data|contains: '"code"'
selection_code_field_raw_request:
RawRequest|contains: '"code"'
selection_code_field_request_body_alt:
request_body|contains: '"code"'
selection_code_field_escaped_requestbody:
RequestBody|contains: '\"code\"'
selection_code_field_urlencoded_requestbody:
RequestBody|contains: '%22code%22'
selection_dangerous_python_requestbody:
RequestBody|contains:
- 'subprocess'
- 'os.system'
- 'os.popen'
- 'os.exec'
- 'pty.spawn'
- 'socket.socket'
- 'socket.connect'
- '__import__'
- 'importlib'
- 'getattr('
- 'globals('
- 'compile('
- '__dict__['
- 'vars('
- 'import socket'
- 'b64decode'
- 'base64.b64decode'
- 'exec('
- 'eval('
- 'open('
- 'requests.get'
- 'requests.post'
- 'urllib.request'
- 'urlopen('
- 'pathlib'
- 'Path('
- '/proc/self/environ'
- '/var/run/secrets'
- 'open("/etc/passwd"'
- "open('/etc/passwd'"
- 'OPENAI_API_KEY'
- 'ANTHROPIC_API_KEY'
- 'AZURE_OPENAI'
- 'DATABASE_URL'
- 'os.environ'
- 'bash -i'
- '/dev/tcp/'
- 'nc -e'
- 'ncat -e'
selection_dangerous_python_http_body:
http.request.body.content|contains:
- 'subprocess'
- 'os.system'
- 'os.popen'
- 'os.exec'
- 'pty.spawn'
- 'socket.socket'
- 'socket.connect'
- '__import__'
- 'importlib'
- 'getattr('
- 'globals('
- 'compile('
- '__dict__['
- 'vars('
- 'import socket'
- 'b64decode'
- 'base64.b64decode'
- 'exec('
- 'eval('
- 'open('
- 'requests.get'
- 'requests.post'
- 'urllib.request'
- 'urlopen('
- 'pathlib'
- 'Path('
- '/proc/self/environ'
- '/var/run/secrets'
- 'open("/etc/passwd"'
- "open('/etc/passwd'"
- 'OPENAI_API_KEY'
- 'ANTHROPIC_API_KEY'
- 'AZURE_OPENAI'
- 'DATABASE_URL'
- 'os.environ'
- 'bash -i'
- '/dev/tcp/'
- 'nc -e'
- 'ncat -e'
selection_dangerous_python_postdata:
post_data|contains:
- 'subprocess'
- 'os.system'
- 'os.popen'
- 'os.exec'
- 'pty.spawn'
- 'socket.socket'
- 'socket.connect'
- '__import__'
- 'importlib'
- 'getattr('
- 'globals('
- 'compile('
- '__dict__['
- 'vars('
- 'import socket'
- 'b64decode'
- 'base64.b64decode'
- 'exec('
- 'eval('
- 'open('
- 'requests.get'
- 'requests.post'
- 'urllib.request'
- 'urlopen('
- 'pathlib'
- 'Path('
- '/proc/self/environ'
- '/var/run/secrets'
- 'open("/etc/passwd"'
- "open('/etc/passwd'"
- 'OPENAI_API_KEY'
- 'ANTHROPIC_API_KEY'
- 'AZURE_OPENAI'
- 'DATABASE_URL'
- 'os.environ'
- 'bash -i'
- '/dev/tcp/'
- 'nc -e'
- 'ncat -e'
selection_dangerous_python_raw_request:
RawRequest|contains:
- 'subprocess'
- 'os.system'
- 'os.popen'
- 'pty.spawn'
- 'socket.socket'
- '__import__'
- 'b64decode'
- 'exec('
- 'eval('
- 'open('
- 'requests.get'
- 'urllib.request'
- '/proc/self/environ'
- 'OPENAI_API_KEY'
- 'DATABASE_URL'
- 'bash -i'
- '/dev/tcp/'
selection_dangerous_python_request_body_alt:
request_body|contains:
- 'subprocess'
- 'os.system'
- 'os.popen'
- 'pty.spawn'
- 'socket.socket'
- '__import__'
- 'b64decode'
- 'exec('
- 'eval('
- 'open('
- 'requests.get'
- 'urllib.request'
- '/proc/self/environ'
- 'OPENAI_API_KEY'
- 'DATABASE_URL'
- 'bash -i'
- '/dev/tcp/'
selection_dangerous_python_regex_requestbody:
RequestBody|re: '(?i)((os|socket|subprocess)\s*\.\s*(system|popen|exec|socket|connect|call|run|check_output)\s*\(|(exec|eval|open|compile)\s*\()'
selection_dangerous_python_regex_http_body:
http.request.body.content|re: '(?i)((os|socket|subprocess)\s*\.\s*(system|popen|exec|socket|connect|call|run|check_output)\s*\(|(exec|eval|open|compile)\s*\()'
selection_dangerous_python_regex_postdata:
post_data|re: '(?i)((os|socket|subprocess)\s*\.\s*(system|popen|exec|socket|connect|call|run|check_output)\s*\(|(exec|eval|open|compile)\s*\()'
selection_dangerous_python_regex_request_body_alt:
request_body|re: '(?i)((os|socket|subprocess)\s*\.\s*(system|popen|exec|socket|connect|call|run|check_output)\s*\(|(exec|eval|open|compile)\s*\()'
filter_main_authorized_regression_test:
c-useragent|contains:
- 'Langflow-SecurityRegression'
condition: >
1 of selection_endpoint_*
and 1 of selection_http_post_*
and 1 of selection_code_field_*
and 1 of selection_dangerous_python_*
and not 1 of filter_main_*
fields:
- c-ip
- x-forwarded-for
- cs-host
- cs-method
- HttpMethod
- http.request.method
- cs-uri-stem
- Uri
- Url
- url.path
- request_uri
- cs-username
- c-useragent
- sc-status
- RequestBody
- http.request.body.content
- post_data
- request_body
- RawRequest
falsepositives:
- Authorized security regression testing against a patched Langflow instance with a tagged user agent
- Internal developers authoring custom Langflow components that legitimately import os, subprocess, or socket for real integrations, expected to be rare and traceable to a known engineering account
level: high
tags:
- attack.initial-access
- attack.execution
- attack.t1190
- attack.t1059
- attack.t1059.006
- attack.credential-access
- attack.t1552
- cve.2026-9198