CVE-2026-57279 in Garoon
Summary
by MITRE • 08/10/2026
Cybozu Garoon contains a cross-site scripting vulnerability. If this vulnerability is exploited, an arbitrary script may be executed in the web browser of a user logged in to the product.
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Analysis
by VulDB Data Team • 08/10/2026
The Cybozu Garoon platform presents a critical cross-site scripting vulnerability that fundamentally undermines the security posture of authenticated users within its web interface. This weakness resides in the application's failure to properly sanitize user input before rendering it in web pages, creating an avenue for malicious actors to inject and execute arbitrary JavaScript code within the context of a victim's browser session. The vulnerability specifically affects scenarios where user-supplied data is processed and displayed without adequate validation or encoding mechanisms, allowing attackers to craft malicious payloads that exploit this input handling flaw.
The technical exploitation of this XSS vulnerability follows standard attack patterns where an attacker crafts a specially crafted request containing malicious script code that gets stored or reflected within the application's response. When a logged-in user accesses the vulnerable page, their browser executes the injected script with the privileges and session context of that authenticated user, potentially enabling complete account compromise. This type of vulnerability falls under CWE-79 which specifically addresses cross-site scripting flaws in web applications, representing one of the most prevalent and dangerous categories of web application security weaknesses.
The operational impact of this vulnerability extends far beyond simple data theft or display manipulation. An attacker who successfully exploits this weakness can perform actions on behalf of authenticated users including accessing sensitive corporate data, modifying user permissions, conducting privilege escalation attacks, or even establishing persistent backdoors within the application environment. The risk is particularly severe for enterprise environments where Garoon serves as a collaboration platform for business-critical operations, as compromised sessions could lead to widespread data breaches and operational disruption. This vulnerability directly maps to several ATT&CK techniques including initial access through malicious content delivery and privilege escalation via session hijacking.
Mitigation strategies for this vulnerability require immediate implementation of robust input validation and output encoding mechanisms throughout the application's codebase. Organizations should implement comprehensive content security policies that prevent script execution in user-controllable contexts, enforce strict sanitization of all user-supplied input before storage or display, and deploy web application firewalls to detect and block suspicious request patterns. Additionally, regular security testing including automated scanning and manual penetration testing should be conducted to identify similar vulnerabilities across the entire application stack. The fix must address both reflected and stored XSS scenarios, ensuring that all user input is properly escaped or validated before being rendered in any HTML context, thereby preventing the execution of malicious scripts within authenticated sessions.