CVE-2026-20634 is a vulnerability identified in Apple’s macOS and other related operating systems such as iOS, iPadOS, watchOS, tvOS, and visionOS. The flaw stems from improper memory handling during the processing of image files, which can be maliciously crafted to cause disclosure of process memory. This means that when a user opens or processes a specially designed image, parts of the memory used by the process handling the image may be exposed, potentially leaking sensitive information such as cryptographic keys, passwords, or other private data stored in memory. The vulnerability does not require elevated privileges but does require user interaction, such as opening or previewing the malicious image. The CVSS v3.1 base score is 5.5, reflecting a medium severity level, with the vector indicating local attack vector (AV:L), low attack complexity (AC:L), no privileges required (PR:N), user interaction required (UI:R), unchanged scope (S:U), high confidentiality impact (C:H), no integrity impact (I:N), and no availability impact (A:N). Apple addressed this issue by improving memory handling in the affected components and released patches in multiple OS versions including macOS Tahoe 26.3, Sonoma 14.8.4, Sequoia 15.7.4, iOS 18.7.5, iPadOS 18.7.5, watchOS 26.3, tvOS 26.3, visionOS 26.3, and iOS/iPadOS 26.3. There are no known exploits in the wild, but the vulnerability poses a risk of sensitive data leakage if exploited. The vulnerability affects a broad range of Apple devices given the multiple OS versions involved.

The primary impact of CVE-2026-20634 is the potential disclosure of sensitive process memory, which can lead to leakage of confidential information such as authentication tokens, encryption keys, or personal data. While the vulnerability does not affect system integrity or availability, the confidentiality breach can have serious consequences for individuals and organizations relying on Apple devices for secure communications and data storage. Attackers with local access could craft malicious images to trick users into opening them, thereby exposing sensitive memory contents. This could facilitate further attacks such as credential theft, unauthorized access, or espionage. The requirement for user interaction and local access limits the attack surface, but the widespread use of Apple devices in enterprise, government, and consumer environments increases the risk. Organizations handling sensitive data on Apple platforms must consider this vulnerability a significant privacy and security concern, especially in environments where users might be targeted with malicious files.

To mitigate CVE-2026-20634, organizations and users should promptly apply the security updates released by Apple for all affected operating systems, including macOS Tahoe 26.3, Sonoma 14.8.4, Sequoia 15.7.4, iOS 18.7.5, iPadOS 18.7.5, watchOS 26.3, tvOS 26.3, and visionOS 26.3. Beyond patching, organizations should implement strict controls on the handling and opening of image files, especially those received from untrusted or unknown sources. Employ endpoint protection solutions that can detect and block suspicious file formats or anomalous image processing behavior. Educate users about the risks of opening unsolicited or unexpected image files, particularly in environments where targeted attacks are possible. Use application whitelisting and sandboxing techniques to limit the ability of malicious files to access sensitive memory regions. Monitor systems for unusual memory access patterns or crashes related to image processing components. Finally, consider network segmentation to limit local access to critical Apple devices and reduce the risk of local exploitation.