NATS Server: `no_auth_user` pre-CONNECT fast path bypasses user connection restrictions (nats-io nats-server)
At a glance
- Source
- NVD
- EPSS
- EPSS 0.29 % · percentile 22 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- GitHub_M
- NVD status
- Analyzed
Description
NATS Server is a high-performance server for NATS.io, the cloud and edge native messaging system. Prior to 2.14.3 and 2.12.12, a client could be registered as the configured no_auth_user through a parser path used when the first client operation was not CONNECT, bypassing user-level connection restrictions such as allowed_connection_types or proxy_required that normal authentication would apply. This issue is fixed in versions 2.14.3 and 2.12.12.
Weaknesses (CWE)
- CWE-863 — Incorrect Authorization
References
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 3.1 | MEDIUM 5.4 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N | GitHub_M |
| CVSS 3.1 | MEDIUM 5.4 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N | NVD · security-advisories@github.com (Secondary) |
European references
- ENISA EUVD · EUVD-2026-42390
- GCVE · GCVE-0-2026-58211
Affected configurations (NVD CPE)
cpe:2.3:a:linuxfoundation:nats-server:*:*:*:*:*:*:*:*≥ 2.12.0 < 2.12.12cpe:2.3:a:linuxfoundation:nats-server:*:*:*:*:*:*:*:*≥ 2.14.0 < 2.14.3
Affected products
| Product | Versions |
|---|---|
| nats-io · nats-server | affected < 2.12.12 ; affected >= 2.14.0-RC.1, < 2.14.3 |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |