---
id: CVE-2026-58250
title: >-
  NATS Server is a high-performance server for NATS.io, the cloud and edge
  native messaging system
summary: >-
  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 se…
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-476
vendor: linuxfoundation
product: nats-server
affected:
  - nats-server < 2.11.17
  - 'nats-server >= 2.12.0, < 2.12.8'
patched:
  - nats-server 2.12.8
published: '2026-07-08'
updated: '2026-07-13'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-58250'
references:
  - url: >-
      https://github.com/nats-io/nats-server/commit/8dcb26eaea78fdcbe96dbee5986d6019fd5cb94a
    label: security-advisories@github.com
  - url: >-
      https://github.com/nats-io/nats-server/commit/fc5fe39177533e9dbdd651d2458285bfae1dde27
    label: security-advisories@github.com
  - url: 'https://github.com/nats-io/nats-server/releases/tag/v2.11.17'
    label: security-advisories@github.com
  - url: 'https://github.com/nats-io/nats-server/releases/tag/v2.12.8'
    label: security-advisories@github.com
  - url: >-
      https://github.com/nats-io/nats-server/security/advisories/GHSA-3g5q-cfh2-cq67
    label: security-advisories@github.com
tags:
  - nvd
epss: 0.00742
epssPercentile: 0.52729
ingestedAt: '2026-07-13T15:27:34.264Z'
---

## Overview

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.

## Affected

- `nats-server < 2.11.17`
- `nats-server >= 2.12.0, < 2.12.8`

## Remediation

Upgrade past the affected range:

- `nats-server 2.12.8`