CVE-2025-6641 is an out-of-bounds read vulnerability identified in the PDF-XChange Editor, specifically affecting version 10.5.2.395. The flaw resides in the parsing of U3D (Universal 3D) files embedded within PDF documents. Due to insufficient validation of user-supplied data during the U3D file parsing process, the application may read memory beyond the allocated buffer boundaries. This out-of-bounds read can lead to the disclosure of sensitive information from the process memory space. While the vulnerability itself does not directly allow code execution, it can be chained with other vulnerabilities to achieve arbitrary code execution within the context of the current process. Exploitation requires user interaction, such as opening a maliciously crafted PDF file or visiting a malicious webpage that triggers the vulnerable parsing routine. The CVSS v3.0 base score is 3.3, reflecting a low severity primarily due to the requirement for local access (AV:L), no privileges required (PR:N), and user interaction (UI:R). The impact is limited to confidentiality loss with no direct effect on integrity or availability. No known exploits are currently reported in the wild, and no patches have been published at this time. The vulnerability was assigned and published by the Zero Day Initiative (ZDI) under the identifier ZDI-CAN-26528. The vulnerability is categorized under CWE-125 (Out-of-bounds Read), a common memory safety issue that can lead to information disclosure and potentially facilitate further exploitation when combined with other flaws.

For European organizations, the primary impact of CVE-2025-6641 is the potential leakage of sensitive information from memory when users open malicious PDF documents containing crafted U3D files. This could expose confidential data such as credentials, cryptographic keys, or other sensitive in-memory information, depending on the context of the PDF-XChange Editor process. Although the vulnerability alone does not allow code execution, attackers may use it as a stepping stone in multi-stage attacks, increasing the risk of full system compromise. Sectors with high reliance on PDF-XChange Editor for document handling, such as legal, financial, and government institutions, could be more vulnerable to targeted information disclosure attacks. The requirement for user interaction limits the attack surface to scenarios involving social engineering or phishing campaigns. Since no known exploits are currently active, the immediate risk is low; however, the vulnerability could become more dangerous if combined with other vulnerabilities or if exploit code is developed. Organizations handling sensitive or classified information should be particularly cautious, as even limited information disclosure can have significant operational or reputational consequences.

1. Restrict usage of PDF-XChange Editor version 10.5.2.395 by enforcing organizational policies to avoid opening PDF files from untrusted or unknown sources, especially those containing embedded 3D content. 2. Implement advanced email filtering and attachment sandboxing to detect and block malicious PDFs with embedded U3D files before reaching end users. 3. Employ endpoint detection and response (EDR) solutions capable of monitoring anomalous behavior related to PDF processing applications. 4. Educate users on the risks of opening unsolicited or suspicious PDF documents and encourage verification of document sources. 5. Monitor vendor communications closely for patches or updates addressing this vulnerability and prioritize timely deployment once available. 6. Consider deploying application whitelisting or restricting execution privileges of PDF-XChange Editor to minimize the impact of potential exploitation. 7. In environments where PDF-XChange Editor is critical, evaluate alternative PDF readers with a lower risk profile or better security track record for handling complex embedded content like U3D files. 8. Conduct regular security assessments and penetration tests focusing on document handling workflows to identify and remediate potential attack vectors involving malicious PDFs.