A stored cross-site scripting vulnerability in SiYuan prior to version 3.8.1 allows authenticated attackers to execute malicious scripts in the browsers of other users.

This is a stored cross-site scripting (XSS) flaw occurring in the confirmDialog() function. The application fails to properly sanitize package and notebook names before rendering them via innerHTML, allowing an authenticated user to inject malicious scripts that execute when other users perform administrative actions like uninstalling packages.

The vulnerability carries a CVSS score of 8.9, reflecting its potential for significant impact on both confidentiality and integrity. Successful exploitation allows attackers to perform unauthorized actions on behalf of victims, potentially leading to the compromise of sensitive notebook data or administrative session hijacking.

Immediate Action: Upgrade SiYuan to version 3.8.1 or later to implement the necessary input sanitization.

Proactive Monitoring: Monitor application logs for suspicious activity involving the installation or removal of bazaar packages, particularly those containing unusual characters in their naming fields.

Compensating Controls: Implement a strict Content Security Policy (CSP) to restrict the sources from which scripts can be executed, reducing the impact of potential XSS attacks.

Public Exploit Available: No (exploit_available: false)

Given the severity of this stored XSS vulnerability, administrators should prioritize updating SiYuan to version 3.8.1 immediately. Failure to patch leaves the environment susceptible to script injection attacks that can bypass standard user permissions and compromise sensitive information stored within the application.