CVE-2026-58250 PUBLISHED

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

Assigner: GitHub_M
Reserved: 29.06.2026 Published: 08.07.2026 Updated: 09.07.2026

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.

Metrics

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS Score: 7.5

Product Status

Vendor nats-io
Product nats-server
Versions
  • Version < 2.11.17 is affected
  • Version >= 2.12.0-preview.1, < 2.12.8 is affected

References

Problem Types

  • CWE-476: NULL Pointer Dereference CWE