NATS has pre-auth server panic via leafnode handling (nats-io nats-server)
At a glance
- Source
- NVD
- EPSS
- EPSS 0.63 % · percentile 50 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- GitHub_M
- NVD status
- Modified
Description
NATS-Server is a High-Performance server for NATS.io, a cloud and edge native messaging system. Prior to versions 2.11.15 and 2.12.6, a client which can connect to the leafnode port can crash the nats-server with a certain malformed message pre-authentication. Versions 2.11.15 and 2.12.6 contain a fix. As a workaround, disable leafnode support if not needed or restrict network connections to the leafnode port, if plausible without compromising the service offered.
Weaknesses (CWE)
References
- https://github.com/nats-io/nats-server/security/advisories/GHSA-vprv-35vv-q339
- https://advisories.nats.io/CVE/secnote-2026-10.txt
- https://access.redhat.com/security/cve/CVE-2026-33218
- https://bugzilla.redhat.com/show_bug.cgi?id=2451450
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-33218.json
- https://access.redhat.com/errata/RHSA-2026:22347
- https://access.redhat.com/errata/RHSA-2026:23345
- https://access.redhat.com/errata/RHSA-2026:21769
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 3.1 | HIGH 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H | GitHub_M |
| CVSS 3.1 | HIGH 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H | redhat-SADP |
| CVSS 3.1 | HIGH 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H | NVD · security-advisories@github.com (Secondary) |
| CVSS 3.1 | HIGH 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H | NVD · 0b0ca135-0b70-47e7-9f44-1890c2a1c46c (Secondary) |
Advisories
- GHSA-vprv-35vv-q339 — NATS has pre-auth server panic via leafnode handling
- GO-2026-4837 — NATS has pre-auth server panic via leafnode handling in github.com/nats-io/nats-server
European references
- ENISA EUVD · EUVD-2026-15968
- GCVE · GCVE-0-2026-33218
Affected configurations (NVD CPE)
cpe:2.3:a:linuxfoundation:nats-server:*:*:*:*:*:*:*:*< 2.11.15cpe:2.3:a:linuxfoundation:nats-server:*:*:*:*:*:*:*:*≥ 2.12.0 < 2.12.6
Affected products
| Product | Versions |
|---|---|
| nats-io · nats-server | affected < < 2.11.15 ; affected >= 2.12.0-RC.1, < 2.12.6 |
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 |