CVE-2025-62024 is a medium-severity cross-site scripting (XSS) vulnerability affecting Jonathan Jernigan's Pie Calendar software versions up to and including 1.2.9. The vulnerability stems from improper neutralization of user-supplied input during web page generation, which allows an attacker to inject malicious scripts into the calendar's web interface. Exploitation requires network access, low attack complexity, and limited privileges (PR:L), with user interaction necessary to trigger the malicious payload. The vulnerability impacts confidentiality, integrity, and availability (C, I, A all low), and the scope is changed (S:C), meaning the attack can affect resources beyond the initially compromised component. Although no known exploits are currently reported in the wild, the vulnerability poses a risk of session hijacking, data theft, or defacement of calendar data. The lack of available patches necessitates immediate attention to alternative mitigations. The vulnerability is listed in the CVE database with a CVSS v3.1 score of 6.5, reflecting a medium severity level. The affected product is a web-based calendar tool, which is commonly used in organizational environments for scheduling and collaboration, making it a potential target for attackers seeking to leverage XSS for broader compromise or espionage.

For European organizations, this vulnerability could lead to unauthorized access to sensitive scheduling information, session hijacking, or injection of malicious scripts that compromise user accounts or internal networks. The impact is particularly significant for sectors relying heavily on web-based collaboration tools, such as finance, government, healthcare, and education. Attackers could exploit this vulnerability to perform targeted phishing, steal credentials, or disrupt business operations by manipulating calendar data. The medium severity indicates that while the vulnerability is exploitable, it requires user interaction and some privileges, which may limit widespread exploitation but still poses a tangible risk. Organizations with remote or hybrid workforces using Pie Calendar are especially vulnerable due to increased reliance on web applications. The lack of patches increases the risk window, necessitating proactive defenses to prevent exploitation.

1. Implement strict input validation and output encoding on all user-supplied data within the Pie Calendar application to prevent script injection. 2. Deploy and configure Web Application Firewalls (WAFs) with rules specifically targeting XSS attack patterns to block malicious payloads before they reach the application. 3. Enforce Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts in the browser context. 4. Educate users to recognize and avoid interacting with suspicious links or calendar entries that could trigger XSS payloads. 5. Monitor application logs and network traffic for unusual activity indicative of attempted XSS exploitation. 6. Engage with the vendor or community to obtain patches or updates as soon as they become available. 7. Consider isolating or limiting access to the Pie Calendar application to trusted networks or VPNs to reduce exposure. 8. Regularly review and update security configurations and conduct penetration testing focused on web application vulnerabilities.