CVE-2026-58250
NATS Server: Pre-auth server crash via double INFO in leafnode handshake
7.5
HIGH
CVSS 3.1
EPSS 0.73%
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.
How to fix CVE-2026-58250
To remediate CVE-2026-58250, upgrade the affected package to a fixed version below.
- —upgrade to 2.11.17 or later
Is CVE-2026-58250 being exploited?
Low — EPSS is 0.7%, meaning exploitation activity has not been observed at scale.
Affected packages (1)
- from 0, < 2.11.17, >= 2.12.0, < 2.12.8
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | HIGH7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |