CVE-2025-64506 is a heap buffer over-read vulnerability identified in the libpng library, specifically in the png_write_image_8bit function used for writing 8-bit PNG images. Libpng is widely used for reading and manipulating PNG raster images across many applications and platforms. The vulnerability affects versions from 1.6.0 up to but not including 1.6.51. The root cause is a faulty conditional guard that mistakenly allows 8-bit grayscale+alpha, RGB/RGBA, and images with incomplete row data to be processed by code paths intended for 16-bit input. This results in reads of up to 2 bytes beyond the allocated heap buffer, causing out-of-bounds memory access. While this does not directly enable arbitrary code execution or data corruption, it can cause application instability, crashes, or denial of service. Exploitation requires local privileges and user interaction to supply a crafted PNG image that triggers the vulnerable code path. No known exploits are currently in the wild. The vulnerability has been patched in libpng version 1.6.51, and upgrading to this or later versions is recommended. The CVSS v3.1 base score is 6.1, indicating medium severity, with attack vector local, low attack complexity, no privileges required, user interaction needed, and impact limited to confidentiality loss and availability disruption.

For European organizations, the primary impact of CVE-2025-64506 lies in potential denial of service conditions caused by application crashes when processing maliciously crafted PNG images. This can disrupt services that rely on image processing, such as content management systems, graphic design tools, web applications, and any software embedding libpng for image manipulation. Confidentiality impact is limited but possible if sensitive memory is inadvertently exposed during the out-of-bounds read, though no direct data leakage or code execution is reported. The vulnerability requires local access and user interaction, reducing the risk of remote exploitation but still posing a threat in environments where users handle untrusted images, such as email clients or file-sharing platforms. Organizations in sectors with high multimedia usage, including media, publishing, and software development, may face operational disruptions. Failure to patch could also increase exposure to targeted attacks leveraging this vulnerability as part of a multi-stage exploit chain. Overall, the impact is moderate but warrants timely remediation to maintain service availability and security posture.

European organizations should prioritize upgrading libpng to version 1.6.51 or later, where the vulnerability is patched. For environments where immediate upgrade is not feasible, implementing strict input validation and sanitization of PNG images before processing can reduce risk. Employ sandboxing or containerization for applications handling untrusted images to limit the impact of potential crashes. Monitoring application logs for abnormal terminations or errors related to PNG processing can help detect exploitation attempts. Additionally, restricting local user permissions and educating users about the risks of opening untrusted image files can mitigate exploitation likelihood. Security teams should integrate vulnerability scanning for libpng versions into their asset management and patching workflows. Where possible, use alternative image processing libraries with no known vulnerabilities until patches are applied. Finally, maintain regular backups and incident response plans to quickly recover from denial of service incidents.