BIT-MASTODON-2026-46349 Mastodon: LD-Signature Bypass via JSON-LD Named-Graph Restructuring

Mastodon is a free, open-source social network server based on ActivityPub. Prior to 4.5.10, 4.4.17, and 4.3.23, Mastodon's normalization of incoming activities signed with Linked-Data Signatures does not sufficiently protect the activities from a certain class of spoofing, allowing attackers to...