SiYuan stores note and package content and then renders it to HTML using the Lute engine with sanitization enabled. The Lute sanitizer efficiently removes dangerous JavaScript schemes from most attributes, but it does not check the form action or SVG xlink:href attributes, allowing an attacker to embed a JavaScript URL in a stored document that is later rendered during an export preview or when a Bazaar package README is displayed. Once rendered in the Electron desktop renderer, the malicious script can invoke operating‑system commands, giving the attacker full remote code execution over the affected machine. The vulnerability stems from improper sanitization (CWE‑79 poor handling of encoding (CWE‑116), with a potential impact of compromising the confidentiality, integrity, and availability of the host system).

SiYuan Note, an open‑source personal knowledge management system, is affected in all releases prior to version 3.7.1.

The CVSS score of 8.6 classifies this flaw as high severity, and the EPSS score of < 1% indicates a very low but non‑zero exploitation probability. It is not listed in the CISA KEV catalog, suggesting the flaw is not actively leveraged in the wild yet. Exploitation requires the attacker to have the ability to place malicious content into the application’s storage (e.g., by creating or editing a note or uploading a Bazaar package). Once a relevant document is rendered—such as during a user’s providing an indirect path to remote code execution.