SiYuan renders the README of a package without sanitizing raw Markdown, so an embedded script can survive into the webpage. When a user opens the package details, the frontend assigns this unfiltered HTML to innerHTML. Because the Electron process runs with nodeIntegration enabled and contextIsolation disabled, any script executed in the renderer gains full Node API access, allowing the attacker to execute arbitrary system commands. This stored cross‑site scripting flaw therefore escalates directly to remote code execution, undermining the confidentiality, integrity, and availability of the host machine.

The affected product is SiYuan by siyuan-note. All releases up to and including version 3.6.0 contain the vulnerability. The defect was addressed in version 3.6.1; users on that or later releases are no longer affected.

The Common Vulnerability Scoring System assigns a score of 5.3, indicating a moderate severity level. The Exploit Prediction Scoring System rates the likelihood of exploitation below 1 %, and the vulnerability is not listed in the CISA Known Exploited Vulnerabilities catalog. Exploitation requires an attacker to supply a package containing a malicious README; the attack plays out when the victim opens the package details. If the user views the crafted content, the script runs with full system privileges, giving the attacker complete control of the victim's machine. The practical risk is therefore contingent upon users installing or opening untrusted packages, but the potential impact is high when the condition is met.