# CVE-2026-54070: SiYuan: Stored XSS in Bazaar marketplace via package README event handlers

> A stored XSS vulnerability in SiYuan allows attackers to execute arbitrary JavaScript in an Administrator's session via malicious package READMEs.

- **Severity:** High 7.1 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 24 Jun 2026
- **Updated:** 26 Jun 2026
- **Also known as:** GHSA-w7cg-whh7-xp28, GO-2026-5965

## What is CVE-2026-54070?

CVE-2026-54070 is a high-severity cross-site scripting vulnerability in siyuan-note siyuan, published on 24 Jun 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official 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.

Weakness: CWE-79 (Improper Neutralization of Input During Web Page Generation), CWE-184 (Incomplete List of Disallowed Inputs)

## Which versions are affected by CVE-2026-54070?

3 open source packages ship an affected version, including github.com/siyuan-note/siyuan/kernel.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `github.com/siyuan-note/siyuan/kernel` | Go | All versions | 0.0.0-20260628153353-2d5d72223df4 |
| `github.com/siyuan-note/siyuan/kernel` | Go | All versions | 0.0.0-20260628153353-2d5d72223df4 |
| `github.com/siyuan-note/siyuan/kernel` | Go | All versions | 0.0.0-20260628153353-2d5d72223df4 |

## How do I fix CVE-2026-54070?

Upgrade github.com/siyuan-note/siyuan/kernel to 0.0.0-20260628153353-2d5d72223df4 or later.

## Is CVE-2026-54070 being exploited?

There is no known exploitation of CVE-2026-54070 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-54070 and fix it if it is affected.

What it is: CVE-2026-54070 is a high-severity cross-site scripting vulnerability in siyuan-note siyuan, published on 24 Jun 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-54070 in the wild and no public exploit code.

Affected packages and fixed versions:
- github.com/siyuan-note/siyuan/kernel (Go): affected all versions; fixed in 0.0.0-20260628153353-2d5d72223df4
- github.com/siyuan-note/siyuan/kernel (Go): affected all versions; fixed in 0.0.0-20260628153353-2d5d72223df4
- github.com/siyuan-note/siyuan/kernel (Go): affected all versions; fixed in 0.0.0-20260628153353-2d5d72223df4

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-54070/ (Markdown: https://insights.sbomify.com/CVE-2026-54070/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-54070
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-54070
- OSV: https://osv.dev/vulnerability/CVE-2026-54070

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-54070/
Summaries are generated and may contain mistakes; the official description above is the record.