CVE-2026-34453

HIGH NUCLEI

SiYuan: Broken access control in /api/bookmark/getBookmark allows unauthenticated publish visitors to read password-protected bookmarked content

Title source: cna
STIX 2.1

Exploitation Summary

CVE-2026-34453 has a Nuclei detection template available — see the Nuclei card below for the Shodan/FOFA recon queries.

Description

SiYuan is a personal knowledge management system. Prior to version 3.6.2, the publish service exposes bookmarked blocks from password-protected documents to unauthenticated visitors. In publish/read-only mode, /api/bookmark/getBookmark filters bookmark results by calling FilterBlocksByPublishAccess(nil, ...). Because the filter treats a nil context as authorized, it skips the publish password check and returns bookmarked blocks from documents configured as Protected. As a result, anyone who can access the publish service can retrieve content from protected documents without providing the required password, as long as at least one block in the document is bookmarked. This issue has been patched in version 3.6.2.

Nuclei Templates (1)

SiYuan <= v3.6.1 - Bookmark Data Disclosure
HIGHVERIFIEDby 0x_Akoko
Shodan: http.favicon.hash:-1450125239

References (3)

Core 3
Core References
X_Refsource_Misc x_refsource_misc
https://github.com/siyuan-note/siyuan/issues/17246

Scores

CVSS v3 7.5
EPSS 0.0380
EPSS Percentile 88.4%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

CISA SSVC

Vulnrichment
Exploitation poc
Automatable yes
Technical Impact partial

Details

CWE
CWE-863
Status published
Products (3)
b3log/siyuan < 3.6.2
siyuan-note/siyuan 0 - 3.6.2Go
siyuan-note/siyuan < 3.6.2
Published Mar 31, 2026
Tracked Since Apr 01, 2026