A downgrade flaw in macOS allowed prior bypass of code‑signing restrictions, giving an application elevated privileges to access protected user data. This is a privilege‑escalation vulnerability identified as CWE‑862. The flaw has been patched in macOS Tahoe 26 with additional code‑signing checks. An attacker could exploit the weakness to run a malicious app that reads or manipulates sensitive information.

Affected versions are all macOS releases prior to macOS Tahoe 26. The advisory lists Apple macOS as the sole vendor, with no specific version numbers provided beyond the mention that the fix is in Tahoe 26.

The CVSS score of 4.0 and EPSS score of less than 1% indicate a low severity and a small probability of exploitation. The flaw is not listed in the CISA KEV catalog, suggesting that widespread or targeted exploitation has not been observed. Because the flaw requires local installation of a downgraded application, the likely attack vector is a local user or an attacker with physical or remote access who can install software. This positions the vulnerability as a low‑risk privilege escalation that could lead to unauthorized data access.