NATS Server: Incomplete fix for CVE-2026-33249: Leaf node connections bypass Nats-Trace-Dest permission check (nats-io nats-server)
At a glance
- Source
- NVD
- EPSS
- EPSS 0.31 % · percentile 24 ()
- 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 2.12.8, message trace destination checks were applied to ordinary client connections but not consistently to messages arriving through leafnode connections, allowing a leafnode operator to send trace events to subjects that would not otherwise be permitted and to use trace-only behavior to prevent normal delivery or storage of affected messages. This issue is fixed in versions 2.14.3 and 2.12.8.
Weaknesses (CWE)
- CWE-863 — Incorrect Authorization
References
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 4.0 | MEDIUM 5.3 | CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N | GitHub_M |
| CVSS 4.0 | MEDIUM 5.3 | CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X | NVD · security-advisories@github.com (Secondary) |
| CVSS 3.1 | MEDIUM 6.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N | NVD · nvd@nist.gov (Primary) |
European references
- ENISA EUVD · EUVD-2026-42386
- GCVE · GCVE-0-2026-58254
Affected configurations (NVD CPE)
cpe:2.3:a:linuxfoundation:nats-server:*:*:*:*:*:*:*:*< 2.12.8cpe:2.3:a:linuxfoundation:nats-server:*:*:*:*:*:*:*:*≥ 2.14.0 < 2.14.3
Affected products
| Product | Versions |
|---|---|
| nats-io · nats-server | affected < 2.12.8 ; 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 |