CVE-2026-87809

Medium

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.

SeverityMedium

CVSS6.5

Exploit probability—

ProductSiyuan

PublishedSep 9, 2026

First seenSep 9, 2026

Weakness typeCWE-639Authorization bypass through user-controlled key

How to fix

Update

siyuan-note siyuan3.8.2 or later

Vendor advisories

github.com/siyuan-note/siyuan/security/advisories/GHSA-8wx4-fvqw-f5f8

Affected products

Product	Affected versions	Fixed in
siyuan-note siyuan	v < 3.8.2	3.8.2

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