CVE-2025-6648 is a security vulnerability classified as an out-of-bounds read (CWE-125) found in PDF-XChange Editor version 10.5.2.395. The flaw resides in the parsing of U3D (Universal 3D) files within the PDF-XChange Editor. Specifically, the vulnerability arises due to insufficient validation of user-supplied data during the processing of U3D content embedded in PDF documents. This improper validation allows an attacker to read memory beyond the allocated buffer boundaries, potentially disclosing sensitive information from the process memory space. Exploitation requires user interaction, such as opening a maliciously crafted PDF file or visiting a web page that triggers the PDF-XChange Editor to parse a malicious U3D file. Although the vulnerability itself is an information disclosure issue, it can be chained with other vulnerabilities to achieve arbitrary code execution within the context of the current process. The CVSS v3.0 base score is 3.3, indicating a low severity primarily due to the requirement for local access (AV:L), low complexity (AC:L), no privileges required (PR:N), and user interaction (UI:R). No known exploits are currently reported in the wild, and no patches have been officially released at the time of this analysis. The vulnerability was identified and assigned by the Zero Day Initiative (ZDI) as ZDI-CAN-26671 and publicly disclosed on June 25, 2025.

For European organizations, the primary impact of CVE-2025-6648 is the potential leakage of sensitive information from systems running the affected version of PDF-XChange Editor. This could include confidential document contents, memory-resident credentials, or other sensitive data residing in the application’s memory space. While the vulnerability alone does not allow code execution, the possibility of chaining it with other vulnerabilities raises the risk of a more severe compromise. Organizations in sectors handling sensitive or regulated data—such as finance, healthcare, legal, and government—may face increased risks of data breaches or espionage. Since exploitation requires user interaction, phishing or social engineering campaigns could be used to deliver malicious PDFs, increasing the attack surface. The impact on system integrity and availability is minimal in isolation, but the confidentiality breach could lead to reputational damage, regulatory penalties under GDPR, and operational disruptions if further exploitation occurs. The low CVSS score reflects limited immediate risk, but the potential for escalation warrants attention.

1. Immediate mitigation involves educating users to avoid opening PDF files from untrusted or unknown sources, especially those containing 3D content. 2. Disable or restrict the rendering of U3D content within PDF-XChange Editor if configurable, to reduce exposure to the vulnerable code path. 3. Employ endpoint security solutions capable of detecting and blocking malicious PDF files or suspicious behaviors associated with PDF parsing. 4. Monitor for updates from the vendor and apply patches promptly once available, as no official patch is currently released. 5. Implement network-level controls to limit access to external resources that may host malicious PDFs or embedded U3D files. 6. Use application whitelisting and sandboxing to contain the impact of potential exploitation. 7. Conduct regular security awareness training focused on phishing and social engineering to reduce the likelihood of user interaction with malicious files. 8. Review and audit logs for unusual PDF file openings or crashes that may indicate exploitation attempts.