PT-2026-58922

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...

CVE-2026-58253

A flaw was found in NATS Server. When the noauthuser configuration is enabled, a parser optimization intended for client connections can inadvertently apply to route or leafnode listeners. This allows an unauthenticated attacker on an adjacent network to bypass inter-server authentication...

Improper Authentication

Overview github.com/nats-io/nats-server/server is an A simple, secure and performant communications system for digital systems, services and devices. Affected versions of this package are vulnerable to Improper Authentication in the parser fast path for inter-server connections, which applies a...

CVE-2026-58253

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 noauthuser was configured, a parser fast path intended for ordinary client connections could also apply to route or leafnode listeners, allowing an...

CVE-2026-58253 NATS Server: Route API Auth Bypass

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 noauthuser was configured, a parser fast path intended for ordinary client connections could also apply to route or leafnode listeners, allowing an...

EUVD-2026-42375

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 noauthuser was configured, a parser fast path intended for ordinary client connections could also apply to route or leafnode listeners, allowing an...

CVE-2026-58253

NATS Server (affected: prior to 2.14.0, 2.12.7, and 2.11.16) contains a parser fast path vulnerability where no_auth_user handling could apply to route/leafnode listeners, enabling an unauthenticated peer to bypass inter‑server CONNECT authentication and operate with the privileges of that connec...