CVE-2026-58253

Summary

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. This issue is fixed in versions 2.14.0, 2.12.7, and 2.11.16.

Affected Software

VendorProductVersion RangeStatus
nats-ionats-server< 2.11.16affected
nats-ionats-server>= 2.12.0-preview.1, < 2.12.6affected

Weaknesses

  • CWE-287: CWE-287: Improper Authentication

References