CVE-2026-20627 is a vulnerability identified in the handling of environment variables within Apple operating systems including macOS, watchOS, iOS, iPadOS, and visionOS. The root cause is insufficient validation of environment variables, which can be manipulated by a local application to gain unauthorized access to sensitive user data. The vulnerability does not require elevated privileges (PR:N) but does require user interaction (UI:R), such as running a malicious app or opening a crafted file. The attack vector is local (AV:L), meaning the attacker must have some level of access to the device. The vulnerability affects confidentiality (C:H) but does not impact integrity or availability. Apple has addressed this issue by improving validation checks in environment variable processing in updates released for watchOS 26.3, macOS Tahoe 26.3, macOS Sonoma 14.8.4, visionOS 26.3, iOS 26.3, and iPadOS 26.3. The CWE classification is CWE-20, indicating improper input validation. No public exploits have been reported, and the vulnerability was reserved in November 2025 and published in February 2026. This vulnerability highlights the risks associated with environment variable handling and the importance of strict validation to prevent data leakage.

The primary impact of CVE-2026-20627 is the unauthorized disclosure of sensitive user data on affected Apple devices. Since the vulnerability allows local apps to access data they should not, it can lead to privacy breaches, exposure of personal or corporate information, and potential escalation in targeted attacks if sensitive credentials or data are accessed. Although the vulnerability does not affect system integrity or availability, the confidentiality breach can undermine user trust and compliance with data protection regulations. Organizations relying heavily on Apple ecosystems, especially those handling sensitive or regulated data, may face increased risk of data leakage. The requirement for user interaction and local access limits the attack scope somewhat, but social engineering or malicious app distribution could facilitate exploitation. The absence of known exploits reduces immediate risk but patching remains critical to prevent future attacks.

To mitigate CVE-2026-20627, organizations and users should promptly apply the security updates released by Apple for all affected operating systems, including macOS Sonoma 14.8.4, watchOS 26.3, iOS 26.3, iPadOS 26.3, and visionOS 26.3. Beyond patching, organizations should enforce strict application vetting and restrict installation of untrusted or unsigned apps to reduce the risk of malicious local applications exploiting this vulnerability. Employing endpoint protection solutions that monitor for suspicious local app behavior can help detect exploitation attempts. User education to avoid running untrusted applications or opening suspicious files is also important given the user interaction requirement. Additionally, organizations should review and limit environment variable usage and access where possible, and monitor logs for unusual environment variable manipulations. Regular audits of device configurations and adherence to the principle of least privilege will further reduce exposure.