PT-2026-56565 · Nats.Io · Nats Server

Published 2026-07-08 · Updated 2026-07-08 · CVE-2026-58253

Mitre

CVSS v3.1

8.8

High

Base vector

AV:A/AC:L/PR:N/UI:N/S:C/C:L/I:H/A:L

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.

Fix

Improper Authentication

Weakness Enumeration

CWE-287

Related Identifiers

CVE-2026-58253

Affected Products

Nats Server

References · 8

• https://nvd.nist.gov/vuln/detail/CVE-2026-58253 · Security Note
• https://github.com/nats-io/nats-server/releases/tag/v2.12.7 · Note
• https://github.com/nats-io/nats-server/releases/tag/v2.11.16 · Note
• https://github.com/nats-io/nats-server/commit/8b8e1ad4ceed32321e00d4fc6e76be05bc13bca6 · Note
• https://github.com/nats-io/nats-server/commit/7b81dd455ea95960090a84858c7662827948d1b6 · Note
• https://github.com/nats-io/nats-server/security/advisories/GHSA-38x3-76xf-cq45 · Note
• https://github.com/nats-io/nats-server/commit/b86147e81710a52b72a7f7275f91d69f723f5cb3 · Note
• https://github.com/nats-io/nats-server/releases/tag/v2.14.0 · Note