CVE-2025-66498 is a memory corruption vulnerability categorized under CWE-125 (Out-of-bounds Read) found in Foxit PDF Reader, specifically in the 3D annotation feature that parses U3D data embedded within PDF files. The flaw arises from insufficient bounds checking when processing PRC content, a 3D data format used in PDF annotations. When a user opens a PDF containing malformed or specially crafted PRC data, the application may read memory outside the intended buffer boundaries, leading to memory corruption. This can cause application crashes, data leakage, or potentially enable further exploitation such as code execution, although no public exploits are currently known. The vulnerability affects multiple versions of Foxit PDF Reader, including 2025.2.1 and earlier, 14.0.1 and earlier, and 13.2.1 and earlier. The CVSS v3.1 score is 5.3 (medium), reflecting that the attack vector is local (AV:L), requires no privileges (PR:N), but does require user interaction (UI:R). The scope is unchanged (S:U), and the impact on confidentiality, integrity, and availability is low. The vulnerability was published on December 19, 2025, with no patches currently linked, indicating that remediation may still be pending or in development. The flaw primarily threatens environments where users open untrusted or malicious PDF documents containing 3D annotations, which could be weaponized in targeted phishing or social engineering campaigns. Given the widespread use of Foxit PDF Reader in enterprise and government sectors, this vulnerability poses a moderate risk, especially where PDF workflows are critical and 3D annotations are enabled.

For European organizations, this vulnerability could lead to partial compromise of sensitive information or disruption of document workflows if exploited. Memory corruption may cause application crashes, leading to denial of service for users relying on Foxit PDF Reader. While the direct impact on confidentiality and integrity is rated low, attackers could leverage this flaw as a foothold for further exploitation, especially in environments where users frequently handle external PDF files. Sectors such as finance, government, legal, and healthcare, which heavily depend on PDF documents and may use Foxit Reader extensively, could experience operational disruptions or data exposure. The requirement for user interaction limits mass exploitation but does not eliminate targeted attacks, particularly spear-phishing campaigns. Additionally, the lack of a patch at the time of disclosure increases exposure risk. Organizations with strict document handling policies or those that disable 3D annotations may face reduced risk. However, failure to address this vulnerability could result in reputational damage and compliance issues under regulations like GDPR if data leakage occurs.

1. Immediately implement strict policies to avoid opening PDF files from untrusted or unknown sources, especially those containing 3D annotations. 2. Disable or restrict 3D annotation features in Foxit PDF Reader via configuration settings or group policies to prevent parsing of U3D/PRC content. 3. Employ application sandboxing or containerization for PDF readers to limit the impact of potential memory corruption exploits. 4. Monitor and filter inbound emails and documents for suspicious PDF files, utilizing advanced threat protection and sandboxing solutions. 5. Train users to recognize phishing attempts and avoid opening unexpected or suspicious PDF attachments. 6. Maintain an inventory of Foxit PDF Reader versions deployed and plan for rapid patch deployment once official fixes become available. 7. Consider alternative PDF readers with a lower attack surface or better security track records in high-risk environments. 8. Use endpoint detection and response (EDR) tools to detect anomalous behavior indicative of exploitation attempts. 9. Regularly back up critical data and ensure incident response plans include scenarios involving PDF-based attacks. 10. Collaborate with Foxit Software for timely updates and security advisories.