---
id: CVE-2026-87809
title: >-
  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
summary: >-
  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 p…
severity: medium
cvss: 6.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N'
cwe:
  - CWE-639
vendor: siyuan-note
product: siyuan
affected:
  - siyuan < 3.8.2
published: '2026-09-09'
updated: '2026-09-18'
sourceUpdated: '2026-09-18T18:17:33.600'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-87809'
references:
  - url: >-
      https://github.com/siyuan-note/siyuan/security/advisories/GHSA-8wx4-fvqw-f5f8
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/siyuan-before-3.8.2-information-disclosure-via-export-preview
    label: disclosure@vulncheck.com
tags:
  - nvd
  - cve.org
epss: 0.00209
epssPercentile: 0.11306
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-09-18T17:08:58.264762Z'
ingestedAt: '2026-09-13T19:07:50.955Z'
---

## Overview

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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.