CVE-2026-58250CWE-476

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

High · published July 8, 2026

CVSS v3.1
7.5
EPSS
1%
Percentile
54.2
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
7.5 · HIGH
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS v4.0
Not supplied
EPSS
0.00742 · 54.2th percentile
Weakness
CWE-476 · NULL Pointer Dereference
Published
2026-07-08T19:48Z
EPSS history
Timeline
  • 08 JUL 19:48Z
    NATS Server: Pre-auth server crash via double INFO in leafnode handshake
    cvelistv5