CVE-2025-64786 is a security vulnerability identified in Adobe Acrobat Reader versions including 24.001.30264, 20.005.30793, 25.001.20982, 24.001.30273, and 20.005.30803 and earlier. The flaw stems from improper verification of cryptographic signatures (classified under CWE-347), which compromises the integrity checks that Acrobat Reader performs on signed content. This weakness allows an attacker to bypass security features designed to validate the authenticity and integrity of documents or embedded content. As a result, an attacker with local access could exploit this vulnerability to gain limited unauthorized write access to the system or files, potentially modifying content or injecting malicious data without triggering expected security alerts. Exploitation does not require user interaction, increasing the risk if an attacker already has local access. However, the attack vector is local (AV:L), and no privileges are required (PR:N), but user interaction is required (UI:R) according to the CVSS vector, which slightly limits the ease of exploitation. The vulnerability does not impact confidentiality or availability but affects integrity, leading to a CVSS score of 3.3 (low severity). No known exploits have been reported in the wild, and no official patches have been linked at the time of publication. Given Adobe Acrobat Reader's widespread use in document handling, especially in professional and governmental environments, this vulnerability could be leveraged in targeted attacks to subtly alter documents or configurations.

For European organizations, the primary impact of CVE-2025-64786 is the potential unauthorized modification of documents or local files handled by Adobe Acrobat Reader. This could undermine document integrity, leading to risks such as falsified contracts, tampered reports, or corrupted data. Although the vulnerability does not directly compromise confidentiality or availability, the integrity breach can have serious legal and operational consequences, especially in regulated sectors like finance, legal, and government. Since exploitation requires local access, the threat is higher in environments where endpoint security is weak or where attackers can gain physical or remote local access to systems. The lack of required user interaction reduces the attack complexity, but the need for local access limits widespread remote exploitation. European organizations relying heavily on Acrobat Reader for document workflows should be aware of the risk of subtle data manipulation and the potential for attackers to bypass signature verification mechanisms.

1. Monitor Adobe’s official security advisories closely and apply patches immediately once they are released to address CVE-2025-64786. 2. Restrict local access to systems running vulnerable Acrobat Reader versions by enforcing strict access controls and endpoint security policies. 3. Implement application whitelisting and restrict the execution of unauthorized scripts or programs that could exploit this vulnerability. 4. Use file integrity monitoring tools to detect unauthorized changes to critical documents or configurations handled by Acrobat Reader. 5. Educate users about the risks of local exploitation and enforce policies to prevent the installation of unauthorized software or plugins. 6. Consider deploying alternative PDF readers with robust security postures in high-risk environments until patches are available. 7. Employ network segmentation to limit lateral movement if local access is gained by an attacker. 8. Regularly audit and review logs for suspicious activities related to document handling and file modifications.