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CVE-2026-40922

SiYuan: Incomplete sanitization of bazaar README allows stored XSS via iframe srcdoc (incomplete fix for CVE-2026-33066)

Published: Apr 16, 2026Updated: Apr 20, 2026 Sources: CVE List NVD BDUCWE-79
NVD MITRE
5.4CVSSMEDIUM
EPSS Score
0.3%
Top 82.8%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
Patch Available

Description

SiYuan is an open-source personal knowledge management system. In versions 3.6.1 through 3.6.3, a prior fix for XSS in bazaar README rendering (incomplete fix for CVE-2026-33066) enabled the Lute HTML sanitizer, but the sanitizer does not block iframe tags, and its URL-prefix blocklist does not effectively filter srcdoc attributes which contain raw HTML rather than URLs. A malicious bazaar package author can include an iframe with a srcdoc attribute containing embedded scripts in their README. When other users view the package in SiYuan's marketplace UI, the payload executes in the Electron context with full application privileges, enabling arbitrary code execution on the user's machine. This issue has been fixed in version 3.6.4.

CVSS Vector Breakdown

AV:NAC:LPR:LUI:RS:CC:LI:LA:N
Exploitability
AV:NAttack Vector
Network
AC:LAttack Complexity
Low
PR:LPrivileges Required
Low
UI:RUser Interaction
Required
Scope
S:CScope
Changed
Impact
C:LConfidentiality
Low
I:LIntegrity
Low
A:NAvailability
None
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Weaknesses

CWE-79

Affected Products

SiYuanYunnan Liandi Technology Co., Ltd.
On-prem
Enterprise Software / document-mgmt
siyuansiyuan-note
siyuanb3log
On-premWeb App
Web & CMS Plugins / cms-core
yunnan liandi technology co., ltd.commercialCNEnterprise Softwareaka yunnan liandi, liandi
b3logoss-projectWeb & CMS Pluginsaka b3log

Attack Graph

Products CVE Techniques Tactics

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Exploitability

Official Patch Available

MITRE ATT&CK

2 techniques
Execution
Initial Access
View detailed technique mapping

References

https://github.com/siyuan-note/siyuan/releases/tag/v3.6.4
github.com
https://github.com/siyuan-note/siyuan/security/advisories/GHSA-8q5w-mmxf-48jg
github.com
https://github.com/siyuan-note/siyuan/commit/b382f50e1880ed996364509de5a10a72d7409428
github.com
and 2 more references View all →

Timeline

Published
Apr 16, 2026
Last Updated
Apr 20, 2026

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