CVE-2025-66293 is an out-of-bounds read vulnerability classified under CWE-125 found in libpng, a widely used reference library for reading, creating, and manipulating PNG images. The flaw exists in libpng versions prior to 1.6.52 within the simplified API when handling palette PNG images that include partial transparency and gamma correction. Specifically, the vulnerability allows reading up to 1012 bytes beyond the bounds of the png_sRGB_base[512] array due to improper internal state management. The PNG files triggering this vulnerability are valid according to the PNG specification, making detection based on file validity difficult. Exploitation involves processing a crafted PNG image, which can cause the application to read memory out-of-bounds, potentially leading to information disclosure or application crashes (denial of service). The vulnerability is remotely exploitable over a network vector if the application automatically processes images from untrusted sources, but requires user interaction (e.g., opening or previewing the malicious PNG). No privileges or authentication are required to exploit this vulnerability. Although no known exploits are currently in the wild, the widespread use of libpng in numerous applications and platforms makes this a significant risk. The vulnerability has a CVSS v3.1 base score of 7.1, indicating high severity primarily due to its impact on availability and potential confidentiality loss. The recommended remediation is to upgrade libpng to version 1.6.52 or later, where the issue has been fixed.

For European organizations, the impact of CVE-2025-66293 can be substantial, especially for those in industries that heavily rely on image processing, such as media, publishing, software development, and digital marketing. The vulnerability could be exploited to cause denial of service by crashing applications that process PNG images, disrupting business operations. Additionally, the out-of-bounds read may lead to partial information disclosure, potentially exposing sensitive data residing in memory adjacent to the png_sRGB_base array. This could have privacy and compliance implications under regulations like GDPR. Since libpng is embedded in many software products and libraries, including web browsers, image viewers, content management systems, and graphic design tools, the attack surface is broad. European organizations that automatically process user-uploaded images or receive images via email or web services are particularly vulnerable. The requirement for user interaction means phishing or social engineering could be used to deliver malicious PNG files. The lack of known exploits in the wild currently reduces immediate risk, but the high severity score and widespread use warrant proactive mitigation to avoid future exploitation.

To mitigate CVE-2025-66293 effectively, European organizations should: 1) Identify all software and systems that use libpng, including embedded libraries in applications, and verify their libpng version. 2) Prioritize upgrading libpng to version 1.6.52 or later across all affected systems and software dependencies. 3) For third-party applications that bundle libpng, coordinate with vendors to obtain patched versions or apply vendor-provided updates. 4) Implement strict input validation and sandboxing for image processing components to limit the impact of malformed PNG files. 5) Employ network and email filtering to block or quarantine suspicious PNG files from untrusted sources, reducing the risk of user interaction with malicious images. 6) Educate users about the risks of opening unsolicited or suspicious image files, especially in email attachments or downloads. 7) Monitor application logs and system behavior for crashes or anomalies related to image processing that could indicate exploitation attempts. 8) Consider deploying runtime protections such as memory safety tools or exploit mitigation technologies (e.g., ASLR, DEP) to reduce the impact of out-of-bounds reads. These steps go beyond generic patching by addressing detection, prevention, and user awareness.