CVE-2026-24523 in WP FullCalendar Plugin
Summary
by MITRE • 01/23/2026
Exposure of Sensitive System Information to an Unauthorized Control Sphere vulnerability in Marcus (aka @msykes) WP FullCalendar wp-fullcalendar allows Retrieve Embedded Sensitive Data.This issue affects WP FullCalendar: from n/a through <= 1.6.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 01/23/2026
The vulnerability identified as CVE-2026-24523 represents a critical exposure of sensitive system information within the WP FullCalendar plugin for WordPress, specifically affecting versions through 1.6. This issue falls under the category of information disclosure vulnerabilities that can have severe operational implications for affected systems. The vulnerability stems from improper access controls that allow unauthorized parties to retrieve embedded sensitive data through the plugin's functionality. The affected component is the Marcus WP FullCalendar plugin, which is commonly used for calendar management and event scheduling within WordPress environments, making it a potentially attractive target for attackers seeking to gather system intelligence.
The technical flaw manifests in the plugin's handling of sensitive data retrieval operations where access controls are inadequately implemented. Attackers can exploit this weakness to obtain system information that should remain restricted to authorized users or system processes. The vulnerability is particularly concerning because it allows for the exposure of embedded sensitive data that may include system configurations, user information, or other potentially valuable intelligence that could be leveraged for further attacks. This type of information disclosure vulnerability is classified under CWE-200, which specifically addresses the exposure of sensitive information to unauthorized actors. The flaw essentially creates an unauthorized control sphere where malicious parties can access data that should be protected within the system's security boundaries.
The operational impact of this vulnerability extends beyond simple data exposure, as it can facilitate more sophisticated attacks by providing attackers with valuable system intelligence. When attackers can retrieve embedded sensitive data from the WP FullCalendar plugin, they may gain insights into the underlying system architecture, user patterns, or configuration details that can be used to plan targeted attacks. This vulnerability can enable attackers to conduct reconnaissance activities more effectively, potentially leading to privilege escalation or lateral movement within the network. The impact is particularly severe in environments where the plugin is widely used and where the exposed information could be correlated with other data sources to create comprehensive attack profiles.
Mitigation strategies for CVE-2026-24523 should prioritize immediate remediation through plugin updates to versions that address the information disclosure flaw. System administrators should implement strict access controls and monitor plugin usage to detect unauthorized data retrieval attempts. The vulnerability aligns with ATT&CK technique T1213.001, which involves data from information repositories, making it crucial to implement proper access logging and monitoring. Organizations should also consider implementing network segmentation to limit the potential impact of such vulnerabilities and ensure that sensitive data is properly encrypted both at rest and in transit. Additionally, regular security assessments of third-party plugins and components should be conducted to identify similar vulnerabilities before they can be exploited by malicious actors.