CVE-2026-58250

HIGH

NATS Server: Pre-auth server crash via double INFO in leafnode handshake

Title source: cna
STIX 2.1

Description

NATS Server is a high-performance server for NATS.io, the cloud and edge native messaging system. Prior to 2.12.8 and 2.11.17, an unauthenticated peer with network access to a leafnode listener with compression enabled could crash the server during the pre-authentication leafnode handshake by sending repeated leafnode INFO protocol messages before authentication and account setup completed. This issue is fixed in versions 2.12.8 and 2.11.17.

References (5)

Core 5

Scores

CVSS v3 7.5
EPSS 0.0073
EPSS Percentile 50.1%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CISA SSVC

Vulnrichment
Exploitation none
Automatable yes
Technical Impact partial

Details

CWE
CWE-476
Status published
Products (3)
linuxfoundation/nats-server < 2.11.17
nats-io/nats-server < 2.11.17
nats-io/nats-server >= 2.12.0-preview.1, < 2.12.8
Published Jul 08, 2026
Tracked Since Jul 09, 2026