SiYuan has incomplete fix for CVE-2026-33066: XSS

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

5.3 · 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 · score source

EPSS

• CVE-2026-40922: 0.26% estimated exploitation activity in the next 30 days; percentile 17.93 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary The incomplete fix for SiYuan's bazaar README rendering enables the Lute HTML sanitizer but fails to block <iframe tags, allowing stored XSS via srcdoc attributes containing embedded scripts that execute in the Electron context. Affected Package - Ecosystem: Go - Package: github.com/siyuan-note/siyuan - Affected versions: < commit b382f50e1880 - Patched versions: = commit b382f50e1880 Details The renderPackageREADME() function in kernel/bazaar/readme.go renders Markdown README content from bazaar (marketplace) packages into HTML. The original vulnerability allowed stored XSS through unsanitized HTML in READMEs. The fix adds luteEngine.SetSanitize(true) to enable Lute's built-in HTML sanitizer. However, the Lute sanitizer in lute/render/sanitizer.go has a critical gap: 1. <iframe is explicitly commented out of setOfElementsToSkipContent, so iframe tags pass through. 2. The srcdoc attribute is checked against URL-prefix blocklists (javascript:, data:text/html), but srcdoc…

Published by the source

14 Apr 2026, 23:12 UTC

Last modified by the source

24 Apr 2026, 20:30 UTC

Source last checked

26 Oct 2026, 15:19 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-8q5w-mmxf-48jg

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# Patch Next advisory brief: CVE-2026-40922

Advisory: SiYuan has incomplete fix for CVE-2026-33066: XSS
IDs: CVE-2026-40922, GHSA-8q5w-mmxf-48jg
Record: https://patchnext.com/advisories/cve-2026-40922 (revision 1, source checked 26 Oct 2026, 15:19 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 5.3)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: github.com/siyuan-note/siyuan/kernel 0.0.0-20260414013942-62eed37a3263. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/siyuan-note/siyuan/kernel: affected < 0.0.0-20260414013942-62eed37a3263; fixed in 0.0.0-20260414013942-62eed37a3263

## Suggested inspection (read-only)
- Go github.com/siyuan-note/siyuan/kernel: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on github.com/siyuan-note/siyuan/kernel.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-8q5w-mmxf-48jg (GitHub-reviewed advisory GHSA-8q5w-mmxf-48jg lists affected ranges: Go github.com/siyuan-note/siyuan/kernel >=0 <0.0.0-20260414013942-62eed37a3263)

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