{"schemaVersion":3,"id":"CVE-2026-58253","aliases":["UBUNTU-CVE-2026-58253","DEBIAN-CVE-2026-58253"],"status":"published","duplicateOf":null,"title":null,"description":"NATS Server is a high-performance server for NATS.io, the cloud and edge native messaging system. Prior to 2.14.0, 2.12.7, and 2.11.16, when no_auth_user was configured, a parser fast path intended for ordinary client connections could also apply to route or leafnode listeners, allowing an unauthenticated peer to bypass inter-server CONNECT authentication and operate with the privileges associated with that connection type. 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