CVE-2026-20629 is a privacy vulnerability identified in Apple macOS that stems from improper handling of temporary files, which may allow a malicious or compromised application to access user-sensitive data. The vulnerability is classified under CWE-922, which involves issues related to temporary file handling that can lead to information disclosure. Specifically, an app running on affected macOS versions prior to Tahoe 26.3 could exploit this flaw to read sensitive data that should be protected, potentially bypassing intended access controls. The vulnerability requires local access (attack vector: local) and user interaction, but no privileges or authentication, meaning any app a user runs could attempt exploitation if the user consents or interacts. The CVSS v3.1 base score is 5.5 (medium severity), reflecting a high impact on confidentiality but no impact on integrity or availability. The scope remains unchanged, indicating the vulnerability affects only the vulnerable component without extending to other system components. Apple addressed this issue by improving the handling of temporary files in macOS Tahoe 26.3, which prevents unauthorized access to sensitive data stored temporarily during normal operations. There are no known exploits in the wild, suggesting limited active targeting so far. However, the potential for privacy breaches remains significant given the sensitive nature of data involved. The vulnerability affects unspecified macOS versions prior to 26.3, so users should assume all earlier versions are vulnerable until patched. This issue highlights the importance of secure temporary file management to prevent data leakage in operating systems.

The primary impact of CVE-2026-20629 is the unauthorized disclosure of sensitive user data on affected macOS systems. This can lead to privacy violations, exposure of personal or corporate confidential information, and potential downstream risks such as identity theft or corporate espionage. Since the vulnerability requires local access and user interaction, the risk is higher in environments where users may run untrusted or malicious applications, such as in BYOD scenarios or where endpoint security is lax. The lack of impact on integrity and availability means the threat is limited to confidentiality breaches rather than system disruption or data manipulation. Organizations relying on macOS for sensitive workloads, especially in sectors like finance, healthcare, and technology, could face compliance and reputational risks if exploited. The absence of known exploits in the wild reduces immediate urgency but does not eliminate the threat, as attackers may develop exploits after public disclosure. Overall, the vulnerability could facilitate targeted attacks or insider threats aiming to extract sensitive data from macOS endpoints.

To mitigate CVE-2026-20629, organizations and users should promptly update all affected macOS systems to version Tahoe 26.3 or later, where the vulnerability is fixed. Beyond patching, organizations should implement strict application control policies to limit the execution of untrusted or unnecessary applications that could exploit local vulnerabilities. Employ endpoint detection and response (EDR) solutions to monitor for unusual access patterns to temporary files or sensitive data by applications. Educate users about the risks of running unknown software and the importance of cautious user interaction, as exploitation requires user action. Review and harden temporary file handling policies and permissions on macOS systems to minimize exposure. For environments with high security requirements, consider additional sandboxing or containerization of applications to restrict file system access. Regularly audit macOS systems for compliance with security baselines and verify that patches are applied timely. Finally, maintain an incident response plan that includes procedures for investigating potential data exposure incidents related to local application exploits.