Siyuan Note: Six XSS and SQLi Vulnerabilities Disclosed Together, Patched in v3.8.4

Key findings

Six vulnerabilities in Siyuan Note disclosed between Sep 17-19, 2026, including multiple high-severity XSS flaws.
Stored XSS vulnerabilities allow arbitrary code execution in the Electron renderer via crafted notebooks and titles.
SQL injection flaw in graph query function exploitable by read-only users.
Affected versions include Siyuan Note through 3.8.4; patches available in 3.8.3 and 3.8.4.
Access control issue in getDynamicIcon endpoint allows metadata leakage of restricted documents.

On September 19, 2026, a batch of six vulnerabilities affecting Siyuan Note, a personal knowledge management application, were disclosed. The vulnerabilities, spanning from September 17 to September 19, 2026, primarily involve stored cross-site scripting (XSS) and an SQL injection flaw, with several carrying high severity ratings. These issues could allow attackers to execute arbitrary code within the Electron renderer, potentially leading to system compromise.

The majority of the disclosed vulnerabilities are related to improper handling of HTML and script execution within the Siyuan Note application.

Stored Cross-Site Scripting (XSS):
CVE-2026-93923 and CVE-2026-92985 stem from Siyuan Note failing to escape heading style attributes and bookmark labels, respectively. This allows attackers to inject malicious HTML and JavaScript into notebooks, which can be executed when these elements are rendered in the outline, bookmark dock, or dock tree.
CVE-2026-93922 involves the Daily Note picker dialog, where notebook names are rendered as raw HTML without proper escaping. Attackers can create notebooks with malicious HTML payloads in their names, leading to script execution in the Electron renderer with Node.js access when the picker is opened.
CVE-2026-92986 is another XSS vulnerability where document titles are rendered as HTML in the backlink dock tree without escaping. Attackers can exploit this by setting malicious titles through the rename API or crafted notebooks, enabling script execution with access to child_process for command execution.

SQL Injection:
CVE-2026-93591 is an SQL injection vulnerability present in the graph.go query2Stmt function. Due to improper escaping of single quotes in tag values, attackers can inject malicious SQL commands via the getGraph endpoint. This vulnerability affects versions prior to 3.8.3 and can be exploited by read-only token holders or anonymous visitors.

Access Control Flaw:
CVE-2026-93921 is a medium-severity vulnerability where Siyuan Note fails to enforce publish access control in the getDynamicIcon endpoint. This allows read-only token holders to access metadata of restricted documents by making specific calls to the endpoint.

The vulnerabilities primarily affect Siyuan Note versions through 3.8.4 for the XSS flaws, and versions before 3.8.3 for the SQL injection vulnerability. The disclosed patches are available in Siyuan Note version 3.8.4 and 3.8.3. Users are strongly advised to update to the latest version to mitigate these security risks.

The clustered disclosure of these vulnerabilities highlights potential weaknesses in Siyuan Note's handling of user-supplied input, particularly concerning HTML rendering and SQL query construction. The ability for attackers to execute code within the Electron renderer and access system-level functions like child_process underscores the severity of these flaws. Users should prioritize updating their Siyuan Note installations to the patched versions to protect their data and systems from potential compromise. Further monitoring for any exploitation attempts or related advisories is recommended.