Muse, Meta's privileged AI assistant, has a serious zero-day vulnerability
23 September 2026 · filed under 5dc131998993
Ars Technica reported on September 21 that Muse, Meta’s newly deployed AI assistant, contains a serious zero-day vulnerability. According to the report, Muse carries extraordinarily broad privileges within the systems it operates on, a design choice that magnifies the consequences of any flaw discovered in it.
The report identifies a ClickFix attack as one method by which an attacker can completely hijack the assistant. ClickFix is a social-engineering technique that tricks a user into executing a malicious action, typically by presenting a fake prompt or instruction that the user follows manually. The report states this is only one of multiple ways the vulnerability can be exploited, though it does not enumerate the others in detail.
The item was also discussed on Hacker News, where the discussion tracked the original Ars Technica reporting.
The report does not specify a timeline for a patch or an official response from Meta, nor does it detail the exact technical mechanism by which hijacking occurs beyond the ClickFix vector described. It characterizes the flaw’s severity as stemming primarily from the scope of access Muse holds on user systems, rather than from any single exploitation technique.
No further technical breakdown, proof-of-concept details, or vendor statement is included in the available reporting.