Medium 5.3Published Apr 16, 2026

CVE-2026-40922SiYuan: Incomplete sanitization of bazaar README allows stored XSS via iframe srcdoc (incomplete fix for CVE-2026-33066)

Updated under an hour ago (Oct 26, 2026, 12:10 PM ET)

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Every CVE for siyuan-note siyuan

Exploited in the last 30 days

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: 5.3 MEDIUM (v4.0, CNA)CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N
Weakness (CWE): CWE-79
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: GitHub_M
NVD analysis: Modified
Record last updated: Apr 20, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

siyuan-note siyuan siyuan_note:siyuan (from the name)	before 3.6.4	CNA record
b3log siyuan b3log:siyuan	from 3.6.1 before 3.6.4	NVD

References

https://github.com/siyuan-note/siyuan/security/advisories/GHSA-8q5w-mmxf-48jgx-refsource-confirm, exploit, third-party-advisory
https://github.com/siyuan-note/siyuan/commit/b382f50e1880ed996364509de5a10a72d7409428x-refsource-misc, patch
https://github.com/advisories/GHSA-4663-4mpg-879vx-refsource-misc, third-party-advisory
https://github.com/siyuan-note/siyuan/releases/tag/v3.6.4x-refsource-misc, release-notes

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.