GoKawiilMeta's Muse AI assistant found to have zero-day flaw exposing user auth tokens
Security researchers discovered that Meta's new macOS AI assistant Muse contains a vulnerability allowing any locally installed app or terminal command to access the authentication token tied to a user's Muse account, bypassing Apple's built-in permission protections. The flaw also lets outside processes alter numerous undocumented settings, some of which could grant deeper control over connected accounts like WhatsApp, email and calendars. Separately, Amazon has begun blocking Muse from its platform.
GoKawiil's interpretation of the reporting above, not reported fact.
Meta has marketed Muse as being 'built from the ground up for privacy and security,' but this flaw undercuts that claim by showing how easily local malware or scripts could hijack a user's authenticated session across linked services. Because Muse integrates deeply with sensitive personal accounts and device permissions, the exposure could let attackers impersonate users, access private communications, or make unauthorized purchases.
- A zero-day in Muse lets local apps or terminal commands steal authentication tokens.
- The bug bypasses macOS security protections Apple designed to limit app access to sensitive resources.
- Amazon has started blocking Muse from its site amid the security concerns.
Yubico YubiKey 5C NFC — With AI assistants like Muse getting broad access to your accounts, locking down authentication with a hardware security key is a smart countermeasure. A YubiKey adds a physical layer of protection to your email, cloud, and social accounts that malware or a compromised AI agent can't easily bypass. It's a simple, durable way to harden your digital life against exactly the kind of exploit described in this article.
See Yubico YubiKey 5C NFC on Amazon → Affiliate link — we may earn a commission on purchases, at no extra cost to you. Product picked by AI based on this article; it is not a tested recommendation.Source: arstechnica.com, 2026-09-21
Published there as: “Muse, Meta's extraordinarily privileged AI assistant, has a serious 0-day”
Read the original report → The summary and analysis above are GoKawiil's own, written from reporting by the source above. Facts and quotes belong to the original publisher.