NATS Server panic via malicious compression on leafnode port (nats-io nats-server)
At a glance
- Source
- NVD
- EPSS
- EPSS 0.68 % · percentile 53 ()
- 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 2.11.14 and 2.12.5, if the nats-server has the "leafnode" configuration enabled (not default), then anyone who can connect can crash the nats-server by triggering a panic. This happens pre-authentication and requires that compression be enabled (which it is, by default, when leafnodes are used). Versions 2.11.14 and 2.12.5 contain a fix. As a workaround, disable compression on the leafnode port.
Weaknesses (CWE)
- CWE-476 — NULL Pointer Dereference
- CWE-409 — Improper Handling of Highly Compressed Data (Data Amplification)
References
- https://github.com/nats-io/nats-server/security/advisories/GHSA-52jh-2xxh-pwh6
- https://github.com/nats-io/nats-server/commit/a1488de6f2ba6e666aef0f9cce0016f7f167d6a8
- https://advisories.nats.io/CVE/secnote-2026-04.txt
- https://access.redhat.com/security/cve/CVE-2026-29785
- https://bugzilla.redhat.com/show_bug.cgi?id=2451444
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-29785.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-52jh-2xxh-pwh6 — NATS Server panic via malicious compression on leafnode port
- GO-2026-4829 — NATS Server panic via malicious compression on leafnode port in github.com/nats-io/nats-server
European references
- ENISA EUVD · EUVD-2026-15963
- GCVE · GCVE-0-2026-29785
CERT-FR advisories
- CERTFR-2026-AVI-0406 — Multiples vulnérabilités dans les produits Microsoft · cert.ssi.gouv.fr
Affected configurations (NVD CPE)
cpe:2.3:a:linuxfoundation:nats-server:*:*:*:*:*:*:*:*< 2.11.14cpe:2.3:a:linuxfoundation:nats-server:*:*:*:*:*:*:*:*≥ 2.12.0 < 2.12.5
Affected products
| Product | Versions |
|---|---|
| nats-io · nats-server | affected < 2.11.14 ; affected >= 2.12.0-RC.1, < 2.12.5 |
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 |
| CERT-FR (ANSSI) | Licence Ouverte / Etalab 2.0 |
| 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 |