Files downloaded from the internet may not receive the quarantine flag, which allows malicious payloads to bypass macOS security checks and potentially execute. This policy flaw can be exploited to compromise system integrity by running code that would otherwise be blocked by Gatekeeper, leading to unauthorized operations.

Apple macOS is affected. The issue is fixed in macOS Sequoia 15.3, meaning all earlier releases are vulnerable until they receive the update.

The CVSS score of 5.3 indicates moderate severity, and the EPSS score of less than 1% suggests a low likelihood of exploitation. The vulnerability is not listed in CISA’s KEV catalog. Based on the description it is inferred that the attack vector is local – a user must download a file, so exploitation requires user action or social engineering. Once a file is downloaded without quarantine, Gatekeeper validation fails, allowing potentially harmful code to run.