CVE-2026-20656 is a logic flaw in Apple Safari that allows a local application with limited privileges to access the user's browsing history without proper authorization. The root cause is inadequate validation in Safari's handling of history data, which could be exploited by an app to bypass intended access controls. This vulnerability affects Safari on iOS, iPadOS, and macOS platforms prior to versions iOS 18.7.5, iPadOS 18.7.5, and Safari 26.3 on macOS Tahoe 26.3. The issue was identified and addressed by Apple through improved validation mechanisms that restrict unauthorized access to browsing history. The vulnerability is classified under CWE-285 (Improper Authorization). The CVSS v3.1 base score is 3.3, indicating low severity due to the requirement for local privileges (AV:L), low attack complexity (AC:L), and no user interaction (UI:N). The impact is limited to confidentiality loss of browsing history, with no effect on integrity or availability. No public exploits have been reported, and the flaw was reserved in November 2025 and published in February 2026. This vulnerability primarily poses a privacy risk, potentially exposing sensitive browsing data to malicious local apps.

The primary impact of CVE-2026-20656 is the unauthorized disclosure of a user's Safari browsing history, which compromises user privacy and confidentiality. For organizations, this could lead to exposure of sensitive or proprietary information if employees use Safari on vulnerable Apple devices and run untrusted local applications. Although the vulnerability does not affect data integrity or system availability, the leakage of browsing history can facilitate targeted phishing, social engineering, or further attacks by revealing user interests, habits, or confidential research. The requirement for local privileges limits remote exploitation, reducing the overall risk to enterprise networks. However, in environments where devices are shared or where malicious insiders or compromised apps exist, the threat is more significant. The absence of known exploits in the wild suggests limited active exploitation, but the vulnerability should still be addressed promptly to maintain user trust and data privacy compliance.

To mitigate CVE-2026-20656, organizations and users should immediately update affected Apple devices to iOS 18.7.5, iPadOS 18.7.5, and Safari 26.3 on macOS Tahoe 26.3 or later, where the vulnerability is fixed. Beyond patching, organizations should enforce strict application control policies, such as using Apple’s MDM solutions to restrict installation of untrusted or unsigned apps that could exploit local vulnerabilities. Employing endpoint protection that monitors and restricts app behaviors accessing sensitive data can further reduce risk. Regularly auditing installed applications and their permissions helps identify potential threats. User education on the risks of installing unverified apps and the importance of timely updates is also critical. For high-security environments, consider disabling Safari history synchronization or using privacy-focused browsing modes to limit data exposure. Finally, monitor device logs for unusual local app activity that might indicate attempts to access browsing history.