CVE-2026-72915: Mastodon

High severity, CVSS 7.5. EPSS: 0.5% chance of exploitation in the next 30 days.

Mastodon is a free, open-source social network server based on ActivityPub. From 4.6.0-beta.1 until 4.6.4 and 4.7.0-beta.1, any logged-in local user could use the show action in app/controllers/admin/collections_controller.rb to access personally identifying information about another local user in a collection because the controller used the general collection policy instead of the admin collection policy namespace. The exposed data included the other user's current email address and last-used IP address. This issue is fixed in versions 4.6.4 and 4.7.0-beta.1.

Affected products

• Mastodon Mastodon: from 4.6.0-beta.1, before 4.6.4 (fixed in 4.6.4)

Published 2026-08-10. Last modified 2026-09-09.