Meta Muse already has a majorly worrying zero-day security issue

The company has been informed, but is yet to comment, or issue a patch

by · TechRadar

News By Sead Fadilpašić Published 22 September 2026

(Image credit: Meta)

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  • Researcher Patrick Wardle finds zero‑day in Meta’s new Muse AI assistant,
  • Dubbed not‑a‑mused, the exploit requires local compromise, voice dictation, and app integrations; attackers can hijack tokens and exfiltrate data
  • Meta has been informed but no patch yet; flaw highlights risks of AI assistants with broad permissions

Meta’s new Artificial Intelligence (AI) assistant Muse reportedly carried a zero-day vulnerability that allowed attackers to gain access to people’s apps, such as WhatsApp or email.

However, it’s not as straightforward as your usual zero-day - to exploit it, simply deploying malware will not suffice. Certain features need to be enabled, and certain integrations established before the bug could be leveraged.

Not-a-mused

A little background, for context: Meta recently released Muse, describing it as an assistant that can “book appointments, fill out forms, and handle customer service.” It says the tool, available exclusively for the Mac ecosystem for now, “proactively takes tasks off your plate” and makes purchases, generates images, and creates documents.

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To do that, however, it needs to connect to apps such as email, WhatsApp, calendar, or social media accounts - and this connection is the first prerequisite needed to exploit the flaw.

The second prerequisite is voice dictation. The vulnerability was found in the way Muse handles commands received via voice, meaning the attacker must piggyback onto voice commands in order to escalate privileges and access other apps and their content.

Now for the flaw itself. It was discovered by security researcher Patrick Wardle, founder of nonprofit Objective-See. He named it “not-a-mused” and says it hides in an undocumented setting called endo_voyager_dictation_endpoint. When a user narrates a voice command, that instruction is sent and processed in the cloud, where Meta can log it. This setting allows the user to change which endpoint receives the dictation.

Which brings us to the third prerequisite. The threat actor must have local access to be able to change this setting in the first place. In other words, the device must already be compromised in some way, either via remote monitoring and management tools, or via low-level malware (or with physical access).

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