High severity · published Jun 24, 2026
CVE-2026-54070
SiYuan: Stored XSS in Bazaar marketplace via package README event handlers
7.1
CVSS
0.3%
EPSS
No
On KEV
Description
SiYuan is an open-source personal knowledge management system. Prior to 3.7.0, renderPackageREADME in kernel/bazaar/readme.go renders a Bazaar package README from Markdown to HTML with the lute engine and SetSanitize(true). The lute sanitizer is an event-handler blocklist: allowAttr rejects only attribute names present in a fixed eventAttrs map copied from the w3schools legacy handler list. That map omits modern event handlers. onpointerover, onpointerdown, onauxclick, onbeforetoggle, onfocusin, onanimationstart, and ontransitionend are not in the list, so the sanitizer passes them through verbatim on any tag. The frontend assigns the rendered HTML to mdElement.innerHTML in app/src/config/bazaar.ts with no client-side DOMPurify on this path, into a normal element in the main document (no iframe, no sandbox). The kernel sends no Content-Security-Policy, X-Frame-Options, or X-Content-Type-Options header on any response, so an inline handler runs when its event fires. The README is rendered when an Administrator opens a package in Settings → Marketplace, after the one-time marketplace trust consent. Install is not required. Result: a third-party Bazaar package author runs JavaScript in the Administrator's authenticated SiYuan origin when the Administrator views and interacts with the package listing, and gains full control of the workspace. This vulnerability is fixed in 3.7.0.
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:L
Attack vector
Network
Complexity
High
Privileges
None
User interaction
Required
Confidentiality
High
Integrity
High
Availability
Low
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 23% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
SI
siyuan · siyuan-note
< 3.7.0 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-54070
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-54070
github.com
https://github.com/siyuan-note/siyuan/security/advisories/GHSA-w7cg-whh7-xp28
More from siyuan
10.0
CVE-2026-72811
SiYuan before v3.7.4 SQL Injection via backlink search
10.0
CVE-2026-69085
SiYuan before v3.7.3 SQL Injection via searchDocs
10.0
CVE-2026-69084
SiYuan before v3.7.3 SQL Injection via searchEmbedBlock
10.0
CVE-2026-69083
SiYuan before v3.7.3 SQL Injection via fullTextSearchAssetContent
10.0
CVE-2026-66012
SiYuan before v3.7.2 Unauthenticated Administrator Takeover via MCP
