Apple’s silicon has long been considered the gold standard for consumer hardware security, but the brand-new M5 chip just faced its first major reality check. A research team from the Palo Alto-based firm Calif recently demonstrated a zero-day exploit that grants full root access on macOS—and they managed the feat in just five days with a little help from Anthropic’s Claude Mythos AI.

From Standard User to Superuser

The exploit is surprisingly elegant in its execution but devastating in its reach. Starting from a standard, unprivileged local user account, the attack uses ordinary system calls to climb the ladder directly to root (administrator) status. This isn't just a simple software bug; it's a "data-only kernel local privilege escalation chain." Essentially, the AI helped researchers find a path to manipulate kernel data without triggering traditional alarms, giving an attacker total control over the machine.

Outsmarting the M5’s Best Defenses

What makes this particularly significant is that it bypasses Apple’s Memory Integrity Enforcement (MIE). MIE was designed as a robust, long-term defense strategy to stop exactly this kind of memory corruption attack. However, by leveraging Claude Mythos, the Calif team was able to navigate the complexities of macOS 26.4.1 and the M5 architecture at a speed that would normally take human researchers months. It appears that while Apple is building better locks, AI is getting exponentially faster at picking them.

The New Frontier of Cyber Threats

This discovery marks a turning point in the cybersecurity landscape. We have officially moved past the era of AI merely drafting phishing emails; we are now seeing generative models identify deep-seated hardware vulnerabilities in next-generation silicon. While the Calif team reportedly delivered the news to Apple in person to facilitate a patch, the exploit serves as a loud wake-up call. As AI moves from a coding assistant to a vulnerability architect, the race between hardware security and AI-driven exploits is about to hit warp speed.

Sources

• Apple M5 architecture suffers first privilege escalation exploit — Anthropic's Claude Mythos helps researchers bypass Memory Integrity Enforcement
• Anthropic Mythos helped Calif build a macOS exploit in five days
• Engineers find two flaws in macOS using Anthropic’s Mythos AI, deliver the news to Apple IN PERSON!