CVE-2025-66495 is a use-after-free vulnerability categorized under CWE-416 found in Foxit PDF Reader's annotation handling functionality. This vulnerability affects multiple versions of Foxit PDF Reader on both Windows and MacOS platforms, specifically versions 2025.2.1 and earlier, 14.0.1 and earlier, and 13.2.1 and earlier. The flaw arises when the software processes a PDF file containing specially crafted JavaScript code that manipulates annotations. During this process, a pointer to memory that has already been freed is accessed or dereferenced, leading to undefined behavior. This memory corruption can be exploited by a remote attacker to execute arbitrary code within the context of the user opening the malicious PDF. The attack vector requires the victim to open a malicious PDF file, implying user interaction is necessary. The CVSS v3.1 base score is 7.8, reflecting a high severity with low attack complexity, no privileges required, but user interaction needed. The impact covers confidentiality, integrity, and availability, as arbitrary code execution could lead to data theft, system compromise, or denial of service. As of the publication date, no known exploits have been reported in the wild, but the vulnerability is publicly disclosed and thus poses a credible threat. The lack of patch links suggests that fixes may be pending or not yet publicly available, emphasizing the need for cautious handling of PDFs from untrusted sources and monitoring for vendor updates.

For European organizations, this vulnerability poses a significant risk due to the widespread use of Foxit PDF Reader in business, government, and critical infrastructure sectors. Successful exploitation could lead to remote code execution, enabling attackers to gain unauthorized access to sensitive data, deploy malware, or disrupt operations. Confidentiality breaches could expose personal data protected under GDPR, leading to regulatory penalties and reputational damage. Integrity and availability impacts could disrupt document workflows, affecting productivity and business continuity. Organizations relying heavily on PDF documents for communication, contracts, and official records are particularly vulnerable. The requirement for user interaction means phishing or social engineering campaigns could be leveraged to deliver malicious PDFs. The absence of known exploits currently provides a window for proactive mitigation, but the public disclosure increases the risk of future exploitation. Overall, the threat could affect a broad range of sectors including finance, healthcare, legal, and public administration across Europe.

1. Immediately monitor Foxit Software's official channels for patches addressing CVE-2025-66495 and apply updates as soon as they become available. 2. Until patches are released, disable or restrict JavaScript execution within Foxit PDF Reader through application settings or group policy to reduce attack surface. 3. Implement email and endpoint security solutions capable of detecting and blocking malicious PDF attachments containing suspicious JavaScript. 4. Educate users on the risks of opening unsolicited or unexpected PDF files, especially those received via email or from untrusted sources. 5. Employ application whitelisting and sandboxing techniques to limit the impact of potential exploitation. 6. Use network-level protections such as intrusion detection/prevention systems tuned to detect anomalous PDF-related activity. 7. Regularly audit and inventory Foxit PDF Reader deployments across the organization to ensure vulnerable versions are identified and remediated. 8. Consider alternative PDF readers with a lower risk profile if immediate patching is not feasible. 9. Maintain robust backup and incident response plans to quickly recover from potential compromises.