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Fencer Vulns
high 7.1

CVE-2026-54070 json

SiYuan: Stored XSS in Bazaar marketplace via package README event handlers

published 2026-06-24 4 mo ago modified 2026-10-25 14 d ago also EUVD-2026-39126 , GHSA-w7cg-whh7-xp28 , GO-2026-5965

cvss
7.1
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 22%
public exploits
0
none known

Summary

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.

Patch / fix

  • go github.com/siyuan-note/siyuan/kernel 0.0.0-20260628153353-2d5d72223df4
  • b3log siyuan 3.7.0
  • govulncheck-vulndb openSUSE Leap 16.0 0.0.20260723T184607-160000.1.1

opensuse advisories openSUSE-SU-2026:21483-1

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
4 mo ago

Exploit prediction

0.30% chance of exploitation in the next 30 days, higher than 22% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.1 CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:L
GitHub 3.1 7.1 CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:L

Affected packages

ecosystem package affected fixed in
go github.com/siyuan-note/siyuan/kernel
<0.0.0-20260628153353-2d5d72223df4
0.0.0-20260628153353-2d5d72223df4

Affected products

  • siyuan-note siyuan

Classification

Weakness
  • CWE-79 Improper Neutralization of Input During Web Page Generation
  • CWE-184 Incomplete List of Disallowed Inputs

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.