CVE-2025-68979 is an authorization bypass vulnerability found in the SimpleCalendar Google Calendar Events plugin, specifically affecting versions up to and including 3.5.9. The vulnerability stems from incorrectly configured access control mechanisms that rely on a user-controlled key to authorize access to calendar events. Attackers can exploit this flaw by manipulating the key parameter, effectively bypassing authorization checks and gaining unauthorized access to calendar event data or functionalities that should be restricted. This type of vulnerability is critical in calendar management plugins because it can lead to unauthorized disclosure of sensitive scheduling information or unauthorized modifications, potentially impacting organizational operations and privacy. The vulnerability does not require prior authentication, which lowers the barrier for exploitation. Although no known exploits have been reported in the wild, the risk remains significant due to the nature of the flaw. The lack of a CVSS score means severity must be assessed based on impact and exploitability factors. The plugin is widely used in WordPress environments that integrate Google Calendar events, making it a relevant threat vector for organizations relying on these tools for scheduling and event management. The vulnerability was published on December 30, 2025, by Patchstack, with no patch links currently available, indicating that organizations should monitor for updates and apply fixes promptly once released.

For European organizations, this vulnerability poses a risk of unauthorized access to sensitive calendar event data, which may include confidential meetings, personal schedules, or business-critical appointments. Exposure or manipulation of such data can lead to privacy violations, operational disruptions, and potential leakage of strategic information. Organizations in sectors such as finance, government, healthcare, and technology, where calendar data may contain sensitive or regulated information, are particularly at risk. The bypass of authorization controls can also undermine trust in internal collaboration tools and may facilitate further attacks if attackers leverage calendar information for social engineering or lateral movement. Since the vulnerability does not require authentication, attackers can exploit it remotely, increasing the threat surface. The absence of known exploits in the wild reduces immediate risk but does not eliminate the potential for future attacks once exploit code becomes available. The impact on confidentiality and integrity is high, while availability impact is likely low unless combined with other attack vectors.

Organizations should immediately inventory their use of the SimpleCalendar Google Calendar Events plugin and identify affected versions (up to 3.5.9). They should monitor the vendor’s official channels and Patchstack for the release of security patches and apply updates as soon as they become available. In the interim, restrict access to the plugin’s administrative and configuration interfaces to trusted users only, and implement web application firewall (WAF) rules to detect and block suspicious requests attempting to manipulate authorization keys. Review and tighten access control policies related to calendar event data, ensuring that user input controlling authorization keys is sanitized and validated. Consider disabling or limiting the plugin’s functionality if patching is delayed and the risk is deemed unacceptable. Conduct regular security audits and penetration tests focusing on calendar integrations to detect similar authorization issues. Educate users about the risks of unauthorized data exposure and encourage reporting of suspicious activity related to calendar events.