CVE-2026-73050 in SiYuan
Summary
by MITRE • 08/16/2026
SiYuan versions before v3.7.4 fail to validate or escape the color field in attribute-view select options, allowing stored cross-site scripting through eight unescaped render sites. Attackers can inject event-handler attributes by including quotation marks in the color value, executing arbitrary JavaScript when viewing databases containing the malicious select field.
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Analysis
by VulDB Data Team • 08/16/2026
The vulnerability identified in SiYuan versions prior to v3.7.4 represents a critical stored cross-site scripting flaw that undermines the application's security posture through improper input validation and output sanitization. This weakness exists within the attribute-view select options functionality where the color field fails to undergo proper validation or escaping mechanisms before being rendered in the user interface. The vulnerability manifests when attackers craft malicious color values containing quotation marks that trigger event-handler attributes, enabling arbitrary javascript execution upon database view operations. The security implications extend beyond simple data corruption as this flaw allows for persistent malicious code injection that can compromise user sessions and data integrity.
The technical implementation of this vulnerability stems from inadequate sanitization of user-provided input within the attribute-view component of SiYuan's database management interface. When users create or modify select options with color attributes, the application stores these values without proper HTML escaping or validation, creating multiple render sites where unescaped content can be executed as javascript code. The specific mechanism involves attackers embedding quotation marks within color field values to break out of expected attribute contexts and inject malicious event handlers such as onclick, onmouseover, or other DOM-based execution points. This vulnerability affects eight distinct render sites within the application's rendering pipeline, amplifying its potential impact and making it particularly challenging to mitigate comprehensively.
The operational impact of this stored XSS vulnerability creates significant risks for SiYuan users who store database configurations containing malicious color values. Once an attacker successfully injects malicious code through a compromised color field, the payload executes every time users view databases containing the affected select options, potentially leading to session hijacking, data exfiltration, or further exploitation of the victim's system. The persistent nature of stored XSS attacks means that victims remain vulnerable until the malicious content is removed from the database, making this vulnerability particularly dangerous in collaborative environments where multiple users may be affected. This flaw directly violates the principle of least privilege and can enable attackers to escalate their access within the application's ecosystem.
This vulnerability maps to CWE-79 which specifically addresses cross-site scripting flaws through inadequate input validation and output encoding. The weakness also aligns with ATT&CK technique T1566.001 related to spearphishing attachments, as users may unknowingly encounter malicious payloads while viewing database content. Additionally, the persistent nature of stored XSS attacks connects to ATT&CK technique T1584.002 concerning the development of malware, as attackers can establish lasting footholds within the application environment. The vulnerability's impact on user sessions and data integrity also relates to ATT&CK technique T1078.004 which covers valid accounts used for persistence. Organizations should implement comprehensive input sanitization, output encoding, and regular security updates to address this class of vulnerabilities effectively.
Mitigation strategies for this stored XSS vulnerability require immediate implementation of proper input validation and output escaping mechanisms within the attribute-view component. The most effective approach involves implementing strict sanitization of all user-provided color values before storage, ensuring that quotation marks and other potentially dangerous characters are properly escaped or removed. Organizations should also implement Content Security Policy headers to limit script execution capabilities and establish regular security audits to identify similar vulnerabilities in other input fields. Additionally, application developers should consider implementing automated testing for XSS vulnerabilities during the development lifecycle and ensure all database attribute configurations undergo proper validation before being stored. The implementation of these mitigations should follow industry best practices established by standards such as OWASP Top Ten and NIST cybersecurity guidelines to ensure comprehensive protection against similar vulnerabilities.