CVE-2025-5936 is a Cross-Site Request Forgery (CSRF) vulnerability identified in the VR Calendar plugin for WordPress, developed by innate-images-llc. This vulnerability affects all versions up to and including 2.4.7 due to missing or incorrect nonce validation in the syncCalendar() function. Nonces in WordPress are security tokens used to verify that requests originate from legitimate users and prevent unauthorized actions. The absence or improper implementation of nonce validation allows an attacker to craft a malicious request that, when executed by an authenticated site administrator (via clicking a link or visiting a crafted webpage), triggers the calendar synchronization process without their consent. This attack vector does not require the attacker to be authenticated but does require user interaction from an administrator, making it a targeted but feasible threat. The vulnerability impacts the integrity of calendar data by enabling unauthorized sync operations, potentially leading to data manipulation or disruption of calendar functionality. The CVSS v3.1 base score is 4.3 (medium), reflecting the network attack vector, low complexity, no privileges required, but requiring user interaction and limited impact confined to integrity. No known exploits have been reported in the wild as of the publication date. The vulnerability was reserved and published in June 2025, with no official patches linked yet, indicating that mitigation may require manual nonce validation implementation or plugin updates once available.

The primary impact of CVE-2025-5936 is on the integrity of calendar data managed by the VR Calendar plugin. An attacker can cause unauthorized synchronization operations, potentially leading to data inconsistencies, unauthorized data changes, or disruption of calendar services. While confidentiality and availability are not directly affected, the integrity compromise can undermine trust in calendar data and disrupt workflows dependent on accurate scheduling. For organizations relying on this plugin for critical scheduling or event management, this could lead to operational inefficiencies or erroneous information dissemination. Since exploitation requires an administrator to interact with a malicious link, the risk is somewhat mitigated by user awareness but remains significant in environments with less stringent user training or high phishing susceptibility. The vulnerability could be leveraged as part of a broader attack chain, for example, to facilitate social engineering or lateral movement within a compromised network.

To mitigate CVE-2025-5936, organizations should immediately verify if the VR Calendar plugin is installed and identify the version in use. If an updated version with proper nonce validation is released, apply the patch promptly. In the absence of an official patch, administrators should implement manual nonce checks in the syncCalendar() function to ensure that all requests are validated against a secure nonce token before processing. Additionally, restrict administrative access to trusted users and enforce multi-factor authentication to reduce the risk of compromised credentials. Educate administrators about phishing and social engineering tactics to prevent inadvertent interaction with malicious links. Employ web application firewalls (WAFs) with rules to detect and block suspicious CSRF attempts targeting the calendar sync endpoint. Regularly audit plugin usage and monitor logs for unusual calendar synchronization activities. Finally, consider temporarily disabling the syncCalendar() functionality if it is not critical until a secure fix is applied.