CVE-2026-87809 PUBLISHED

Siyuan before v3.8.2 Information Disclosure via Export Preview

Assigner: VulnCheck
Reserved: 09.09.2026 Published: 09.09.2026 Updated: 09.09.2026

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.

CVSS Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
CVSS Score: 7.1

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Network	Confidentiality	High	Confidentiality	None
Attack Complexity	Low	Integrity	None	Integrity	None
Attack Requirements	None	Availability	None	Availability	None
Privileges Required	Low
User Interaction	None

CVSS 4.0

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
CVSS Score: 6.5

Attack Vector	Network	Scope	Unchanged
Attack Complexity	Low	Confidentiality Impact	High
Privileges Required	Low	Integrity Impact	None
User Interaction	None	Availability Impact	None

CVSS 3.1

Product Status

Vendor	siyuan-note
Product	siyuan
Versions	Default: unaffected affected from 0 to 3.8.2 (excl.) Version 3.8.2 is unaffected

References

Problem Types

Authorization Bypass Through User-Controlled Key CWE