CVE-2025-27161 is an out-of-bounds read vulnerability classified under CWE-125 affecting multiple versions of Adobe Acrobat Reader, including 24.001.30225, 20.005.30748, and 25.001.20428 and earlier. The vulnerability arises during the parsing of crafted PDF files, where the software reads beyond the allocated memory buffer, potentially exposing sensitive data or corrupting memory. This memory corruption can be leveraged by attackers to execute arbitrary code within the context of the current user. Exploitation requires user interaction, specifically opening a maliciously crafted PDF file, which triggers the vulnerability. The CVSS v3.1 base score is 7.8, reflecting high severity due to the combination of local attack vector, low attack complexity, no privileges required, required user interaction, and high impact on confidentiality, integrity, and availability. Although no public exploits have been reported yet, the vulnerability poses a significant risk given Acrobat Reader's widespread use in enterprises and government agencies. The flaw highlights the importance of secure memory handling in PDF parsing components and the need for timely patching. Adobe has not yet released patches at the time of this report, so users should exercise caution when handling PDF files from untrusted sources.

The vulnerability allows attackers to execute arbitrary code with the privileges of the current user, potentially leading to full system compromise if the user has elevated rights. Confidentiality is at risk due to possible memory disclosure from out-of-bounds reads. Integrity and availability can be affected through memory corruption leading to application crashes or malicious code execution. Organizations relying heavily on Adobe Acrobat Reader for document workflows, especially those handling sensitive or classified information, face increased risk of data breaches, espionage, or ransomware attacks. The requirement for user interaction limits remote exploitation but does not eliminate risk, as phishing or social engineering can induce victims to open malicious files. The widespread deployment of Acrobat Reader across industries, including finance, healthcare, government, and education, amplifies the potential impact. Without available patches, organizations remain vulnerable to targeted attacks exploiting this flaw.

Until official patches are released, organizations should implement strict email and file filtering to block or quarantine suspicious PDF attachments. Employ sandboxing or isolated environments for opening untrusted PDF files to contain potential exploitation. Educate users about the risks of opening unsolicited or unexpected PDF documents, emphasizing phishing awareness. Enable and enforce the use of updated antivirus and endpoint detection and response (EDR) solutions capable of detecting exploit attempts targeting Acrobat Reader. Consider disabling or restricting Acrobat Reader usage where possible, or use alternative PDF readers with a better security posture temporarily. Monitor network and endpoint logs for unusual behaviors indicative of exploitation attempts. Once Adobe releases patches, prioritize immediate deployment across all affected systems. Additionally, apply the principle of least privilege to user accounts to limit the impact of potential code execution.