BIT-MASTODON-2025-27399 Mastodon's domain blocks & rationales ignore user approval when visibility set as "users"

Mastodon is a self-hosted, federated microblogging platform. In versions prior to 4.1.23, 4.2.16, and 4.3.4, when the visibility for domain blocks/reasons is set to "users" localized English string: "To logged-in users", users that are not yet approved can view the block reasons. Instance admins...

CVE-2025-27399 Mastodon's domain blocks & rationales ignore user approval when visibility set as "users"

Mastodon is a self-hosted, federated microblogging platform. In versions prior to 4.1.23, 4.2.16, and 4.3.4, when the visibility for domain blocks/reasons is set to "users" localized English string: "To logged-in users", users that are not yet approved can view the block reasons. Instance admins...

CVE-2025-27399

Summary: Mastodon contains an access-control bug where, when domain blocks/reasons visibility is set to the English string “To logged-in users,” users not yet approved can view the block reasons. Affected versions: before 4.1.23, 4.2.16, and 4.3.4. Impact: instance admins who rely on private doma...

CVE-2025-27399 Mastodon's domain blocks & rationales ignore user approval when visibility set as "users"

Mastodon is a self-hosted, federated microblogging platform. In versions prior to 4.1.23, 4.2.16, and 4.3.4, when the visibility for domain blocks/reasons is set to "users" localized English string: "To logged-in users", users that are not yet approved can view the block reasons. Instance admins...

CVE-2025-27399: Exposure of Sensitive Information to an Unauthorized Actor

Mastodon is a self-hosted, federated microblogging platform. In versions prior to 4.1.23, 4.2.16, and 4.3.4, when the visibility for domain blocks/reasons is set to "users" localized English string: "To logged-in users", users that are not yet approved can view the block reasons. Instance admins...