CVE-2026-75948 in iCagenda Extension
Summary
by MITRE • 08/20/2026
Joomla Extension - icagenda.com - Authenticated Stored XSS in iCagenda 4.0.8 to 4.0.12 - The frontend "Submit an Event" form stores the `image` and `file` fields as raw strings with no output-side HTML-attribute escaping.
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Analysis
by VulDB Data Team • 08/20/2026
The vulnerability identified in Joomla Extension icagenda.com versions 4.0.8 through 4.0.12 represents a critical authenticated stored cross-site scripting flaw within the frontend event submission functionality. This security defect arises from insufficient input validation and output encoding mechanisms when handling user-supplied data for image and file upload fields. Specifically, the application accepts raw string inputs for these fields without applying necessary HTML-attribute escaping during subsequent rendering processes. Because this processing occurs on the server side before storage in the database, any malicious script injected by an attacker is persisted within the system's backend infrastructure rather than being executed transiently or discarded immediately upon request submission.
From a technical perspective, the core issue lies in the lack of context-aware output encoding when the stored data is retrieved and displayed to other users or administrators viewing event details. When a user submits an event via the frontend form, they can embed JavaScript code within the image URL or file path fields. Since these values are stored as raw strings without sanitization against HTML special characters such as quotes, angle brackets, or ampersands, the browser interprets them as executable script content when rendered in an HTML attribute context. This allows for the execution of arbitrary client-side scripts under the security context of the web application domain, bypassing same-origin policy restrictions and enabling access to sensitive user data stored within cookies, local storage, or session tokens associated with that domain.
The operational impact of this vulnerability is significant due to its authenticated nature and persistent storage characteristics. An attacker must first possess valid credentials for a low-privileged account capable of submitting events on the frontend interface. Once authenticated, the attacker can craft a malicious payload designed to exfiltrate administrative cookies, hijack active sessions, or perform actions on behalf of other users who view the compromised event listing. This could lead to complete compromise of user accounts, defacement of public-facing pages through injected content, or further pivoting into internal network resources if session tokens provide access to additional services. The stored nature ensures that every subsequent visitor viewing the affected event page becomes a potential victim without requiring any additional interaction from them beyond loading the webpage.
This vulnerability aligns with Common Weakness Enumeration CWE-79, which classifies improper neutralization of input during web page generation as cross-site scripting. Additionally, it maps to MITRE ATT&CK technique T1059, specifically subcategory 007 for JavaScript execution, and potentially T1136 if used for credential harvesting through phishing-like mechanisms within the application context. The attack vector involves initial authentication followed by data injection via a user-facing form, making detection challenging without proper input validation logging or behavioral analysis tools that monitor for anomalous script tags in database fields.
Mitigation strategies should prioritize immediate patching to version 4.0.13 or later where these encoding issues have been addressed at the framework level. In environments where upgrading is not immediately feasible, administrators can implement server-side filtering rules using regular expressions to block common JavaScript event handlers such as onerror, onload, and onclick attributes within image and file fields before database insertion. Additionally, enabling Content Security Policy headers with strict directives regarding script sources can mitigate the impact by preventing execution of inline scripts even if they are successfully stored in the database. Regular security audits focusing on output encoding practices across all user-input-driven display contexts will help prevent similar vulnerabilities from emerging in other parts of the application ecosystem.