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CVE-2026-87809— Siyuan before v3.8.2 Information Disclosure via Export Preview

Quick assessment

Affected
siyuan-note siyuan
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

Siyuan 在 v3.8.2 之前版本中，在通过 /api/export/preview 和 /api/lute/copyStdMarkdown 接口渲染内嵌块（embedded blocks）时，未能正确应用“发布访问权限”（publish-access）过滤。拥有只读权限的攻击者可以通过访问包含引用这些私有、隐藏或禁用发布的块的内嵌查询的公开文档，从而获取这些块完整渲染后的内容。

CVSS 6.5 · Medium
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I. Basic Information for CVE-2026-87809

Vulnerability Information
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Vulnerability Title
Siyuan before v3.8.2 Information Disclosure via Export Preview
Source: CVE Program / CVE List V5
Vulnerability Description
Siyuan before v3.8.2 fails to apply publish-access filtering to embedded blocks before rendering in the /api/export/preview and /api/lute/copyStdMarkdown endpoints. Attackers with reader access can retrieve the full rendered content of private, hidden, or publish-disabled blocks by accessing public documents containing embed queries that select those blocks.
Source: CVE Program / CVE List V5
CVSS Information
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
Source: CVE Program / CVE List V5
Vulnerability Type
通过用户控制密钥绕过授权机制
Source: CVE Program / CVE List V5

Affected Products

Vendor Product Affected Versions CPE Subscribe
siyuan-note siyuan 0 ~ 3.8.2 -

II. Public POCs for CVE-2026-87809

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III. Intelligence Information for CVE-2026-87809

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Vendor Advisories for CVE-2026-87809 (2)

Same Patch Batch · siyuan-note · 2026-09-09 · 9 CVEs total

CVE-2026-87815 8.7 HIGH SiYuan before v3.8.2 Path Traversal via removeRiffDeck
CVE-2026-87807 7.5 HIGH siyuan before v3.8.2 SQL Injection via fullTextSearchBlock
CVE-2026-87814 7.3 HIGH SiYuan before v3.8.2 Stored XSS via Asset Preview
CVE-2026-87811 7.3 HIGH SiYuan before v3.8.2 Stored XSS via notebook template paths
CVE-2026-87813 7.3 HIGH SiYuan before v3.8.2 Stored XSS via unescaped asset filenames
CVE-2026-87812 6.8 MEDIUM SiYuan before v3.8.2 Stored XSS via Bazaar iconURL
CVE-2026-87810 5.3 MEDIUM Siyuan before v3.8.2 Information Disclosure via fullTextSearchBlock
CVE-2026-87808 4.9 MEDIUM SiYuan before v3.8.2 Read-Only Boundary Bypass via fullTextSearchBlock

IV. Related Vulnerabilities

Same product: siyuan
Same vendor: siyuan-note
Same weakness: CWE-639

V. Comments for CVE-2026-87809

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