CVE-2026-73037 in next-ai-draw-io
Summary
by MITRE • 08/13/2026
Next AI Draw.io 0.2.1 through 0.4.16 contains a reflected cross-site scripting vulnerability in the mcp query parameter that is interpolated without escaping into HTML and JavaScript. Attackers can craft malicious URLs to execute arbitrary JavaScript in the localhost origin, enabling exfiltration of diagram sessions and API data.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 08/13/2026
The Next AI Draw.io vulnerability spans versions 0.2.1 through 0.4.16 and represents a critical reflected cross-site scripting flaw that undermines the application's security posture. This vulnerability specifically targets the mcp query parameter which serves as an entry point for malicious input manipulation. The flaw occurs when user-supplied data from this parameter is directly interpolated into HTML and JavaScript contexts without proper sanitization or escaping mechanisms, creating an environment where attacker-controlled content can be executed within the victim's browser session.
The technical implementation of this vulnerability stems from improper input validation and output encoding practices within the application's codebase. When the mcp parameter contains malicious payloads such as javascript:alert(1) or other script tags, these inputs bypass security controls and are rendered directly into the page's HTML structure. This allows attackers to inject arbitrary JavaScript code that executes in the context of the localhost origin, effectively bypassing typical browser security restrictions that prevent cross-origin attacks.
The operational impact of this vulnerability extends beyond simple script execution capabilities, as it enables sophisticated attack vectors for data exfiltration and session manipulation. Attackers can craft malicious URLs that, when visited by unsuspecting users, automatically execute scripts to steal active diagram sessions, extract API keys, and access sensitive user data stored within the application's local storage. The localhost origin context provides attackers with elevated privileges within the victim's browser environment, potentially allowing for session hijacking and unauthorized access to protected resources.
This vulnerability aligns with CWE-79, which specifically addresses cross-site scripting flaws in software applications. From an ATT&CK framework perspective, this represents a T1059.007 technique for executing malicious code through web-based attack vectors. The vulnerability also corresponds to T1566, covering the initial compromise through spearphishing with a link that delivers malicious payloads. Organizations should implement comprehensive input validation measures including proper HTML escaping, Content Security Policy headers, and strict parameter validation to prevent such injection attacks.
Mitigation strategies should include immediate patching of affected versions, implementation of robust input sanitization for all user-supplied parameters, and deployment of web application firewalls with XSS detection capabilities. Security teams must also conduct thorough penetration testing to identify similar vulnerabilities in other application components and establish monitoring procedures for detecting suspicious parameter usage patterns. Additionally, implementing proper output encoding for all dynamic content insertion and establishing security awareness training for developers can significantly reduce the risk of similar vulnerabilities in future releases.
The broader implications of this vulnerability highlight the critical importance of secure coding practices in modern web applications, particularly those handling sensitive data or providing collaborative features. Organizations utilizing Draw.io or similar diagramming tools should perform comprehensive security assessments to identify potential injection points and ensure proper input validation across all application interfaces. Regular security updates and vulnerability scanning procedures remain essential for maintaining protection against evolving attack methodologies targeting web-based applications.