# CVE-2026-41421: SiYuan Desktop Notification XSS Leads to Electron RCE

> Attacker can execute arbitrary code on desktop via XSS in notifications due to insecure Electron configuration.

- **Severity:** High 8.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 24 Apr 2026
- **Updated:** 25 Apr 2026
- **Also known as:** GHSA-grjj-6f6g-cq8q

## What is CVE-2026-41421?

CVE-2026-41421 is a high-severity cross-site scripting vulnerability in siyuan-note siyuan, published on 24 Apr 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

SiYuan is an open-source personal knowledge management system. Prior to 3.6.5, SiYuan desktop renders notification messages as raw HTML inside an Electron renderer. The notification route POST /api/notification/pushMsg accepts a user-controlled msg value, forwards it through the backend broadcast layer, and the frontend inserts it into the DOM with insertAdjacentHTML(...) at message.ts. On desktop builds, this is not limited to ordinary XSS. Electron windows are created with nodeIntegration: true, contextIsolation: false, and webSecurity: false at main.js. As a result, JavaScript executed from the notification sink can directly access Node APIs and escalate to desktop code execution. This vulnerability is fixed in 3.6.5.

Weakness: CWE-79 (Improper Neutralization of Input During Web Page Generation), CWE-78 (Improper Neutralization of Special Elements used in an OS Command)

## Which versions are affected by CVE-2026-41421?


## How do I fix CVE-2026-41421?

No fix has been published for CVE-2026-41421 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-41421 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-41421 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-41421 and fix it if it is affected.

What it is: CVE-2026-41421 is a high-severity cross-site scripting vulnerability in siyuan-note siyuan, published on 24 Apr 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-41421 exists.

Affected product: siyuan-note siyuan. No package-level version data is available, so check the vendor advisory linked from the reference page.

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-2026-41421/ (Markdown: https://insights.sbomify.com/CVE-2026-41421/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-41421
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-41421
- OSV: https://osv.dev/vulnerability/CVE-2026-41421

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-41421/
Summaries are generated and may contain mistakes; the official description above is the record.