# The forum file kept growing

2026-10-11

Commune says about 307,000 community members may be in one file. Sansan's confirmed slice is 1,325 emails. Panasonic's is about 5,000 across two brand forums. The brands are not the platform, and the platform is not each brand's product.

Canonical: https://www.fabiocti.com/notes/the-forum-file-kept-growing/
Author: Fabio Correia

Each brand mailed its own members. The file is still one file.

Commune, the company that runs the community platform, said on 9 October that Commune and Commune for Work were reached on the evening of 5 October, that it noticed on the 6th, and that member information from some communities left. Its ceiling is about 307,000 people across the contract companies that use the service. Internet Watch’s account of the notice: someone obtained invite links to private communities, registered as an ordinary member, then impersonated an administrator to view, take, and overwrite data. Maintenance started the evening of the 6th. On the 7th a leftover path was used for more registrations and viewing, and was cut the same afternoon. Communities that asked to come back started returning on the 8th.

The tenants then counted their own rooms. Sansan’s 9 October notice: the User Forum sat on this cloud. Confirmed leak, 1,325 people: email, display name, the self-introduction, the profile image, and which groups they were in. Another 8,687 may have lost the same fields except the email. Passwords were not in it. Core products, Sansan, Bill One, Contract One, Eight, were not touched. Members were mailed the same day, and the Personal Information Protection Commission was told. ITmedia, the next morning, added Panasonic: about 2,000 on the LUMIX community and about 3,000 on a Panasonic Beauty forum, emails included, on Commune’s report to them. LINE Yahoo, Yamaha, and Suzuki published the same day. Those names are tenants. They are not a second incident.

## What a 1,325-person letter will be asked to mean

It will be briefed as “Sansan lost ten thousand customers.” The ten thousand is Nikkei rounding the confirmed plus the maybe. The product that sells contact data was not the box. The forum was. Panasonic’s 5,000 is two marketing communities, not a factory or a hospital file. The person who holds the 307,000 still has the join: which nickname sat in which brand’s room, with the email where a tenant confirmed it.

If you got Sansan’s mail, the fields they listed are the incident. If you are in a community that has not written yet, you are in the vendor’s ceiling until that letter arrives. Do not treat a business-card scan as exposed because a user forum was. Do not treat the forum as safe because the core product is still up. A community invite link is how a private room becomes a public export.

The brands will keep issuing their own numbers. Add them only after you have subtracted the overlap. The file does not issue a new copy each time a logo speaks.