Five steps to recheck every AI assistant share link you have sent, after Muse put chat titles in DNS

You send a colleague a link to a conversation with an AI assistant to save time, and you name it “Q3 sales team payroll”. This week, Meta’s Muse case showed that the name can travel further than the recipient: the Claroc research team found more than 6,800 Muse share-page addresses in passive DNS data (a store of the domain names that computers have looked up), because Muse builds the address from the conversation’s title. Your job today is to recheck the links you have already shared and change how you name conversations before you share the next one.

What happened with Muse

According to Claroc’s research post of October 18, 2026, Muse (Meta’s AI assistant, launched on September 8, 2026) turns each share into a page that anyone with the link can open, with no login. The page address is made of the conversation’s title plus a random code. When someone opens the page, their browser looks up DNS (the domain name system, which turns a text address into a server address), and a passive DNS service records the hostname (the domain-name part of the address), title included. Claroc says it searched only one commercial passive DNS service, opened a few hundred pages and withheld every identifier in its post. It describes pages holding personal and company-internal documents, such as a home-sale budget or a workplace’s vacation calendar.

After Ars Technica asked Meta, Claroc says Meta told Ars it would suspend the sharing feature. On October 22, 2026, Meta’s David Singleton wrote on X that the underlying issue was fixed and sharing was back on. In his account the flaw was in the URLs (page addresses) of artifacts (documents and images created inside Muse), not in conversation sharing, while Claroc describes conversation share pages as well. For anyone who shared an artifact before the fix, Meta says the old link now shows a note asking the viewer to get the new link from you.

The review below works for any AI assistant: Claroc notes that many assistants share through public links, and that Muse is the one that puts the title in the address.

Recheck the links you have shared

Lan, an accountant at a small company (an example made up for this article), has sent colleagues three links to conversations with an AI assistant.

1. Open the settings or history of the AI assistant you use and find the section that lists shared links (the name differs between apps, often close to “Shared links” or “Share”). Copy the title of each link onto paper.
2. Mark every link whose title states sensitive content outright: a customer name, an amount, a person’s name, a loan file. Lan marks the link “Reconciliation of Company X receivables, September”.
3. Open each marked link in a private (incognito) window, not logged in. If the page still shows its content and you do not want strangers to see it, delete or revoke the link right away in the section from step 1.
4. To send it to a colleague again, rename the conversation to a neutral name such as “Notes 23/10” and create a new link, or send the content by email, as an attachment or through the company’s internal channel.
5. Create a test link from a conversation with made-up content and a harmless title, then look at the link’s address, especially the domain part, which is what stands before the first / after “https://”. If the title sits in the domain part, as in Muse’s home-sale-budget-9f21c8a3.cf.metaaiusercontent.com, that app may let the title reach DNS; a title that appears only after the / does not. Claroc also suggests creating a link yourself to see what lands in the hostname and in the URL.

You are done when every sensitive link you opened in the private window says it has expired, cannot be found or asks for a login, and the list from step 1 holds only the links you meant to keep.

If the app has no section listing shared links, you cannot revoke old links through settings. Ask the app’s administrator or support team, and from now on stop sharing sensitive content by link.

If you manage a team

Claroc advises saying plainly in the company’s AI-use policy that sharing by link means publishing a public page, next to the list of what may be pasted into an assistant. For Muse, Claroc proposes blocking muse.ai and metaaiusercontent.com at the network filter if there is no other way to manage it; Claroc itself calls this a blunt measure.

Sources

1. Claroc Research Team, “GhostShares: A Shared Muse Chat Exposed Prep for a Confidential Call With a Frontier AI Lab Leader” (18/10/2026, updated 20/10) — source for how Muse builds addresses from titles, the 6,800 figure and the advice to organisations; this is research by a security company.
2. David Singleton (Meta) on X, “An update on Muse shared artifacts” (22/10/2026) — Meta’s account of the fix, the new artifact links and the scope of the flaw.
3. The Verge, “Meta turns Muse sharing back on” (22/10/2026) — report on Meta turning sharing back on.