Description
NATS-Server is a High-Performance server for NATS.io, a cloud and edge native messaging system. The nats-server provides an MQTT client interface. Prior to versions 2.11.15 and 2.12.5, Sessions and Messages can by hijacked via MQTT Client ID malfeasance. Versions 2.11.15 and 2.12.5 patch the issue. No known workarounds are available.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| nats-io | nats-server | < 2.11.15, >= 2.12.0-RC.1, < 2.12.6 | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | nats-server | 2.12.6-1 | — |
| Debian 13 | nats-server | No fix yet | — |
| Debian 12 | nats-server | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | nats-server | No fix yet | — |
| Ubuntu 25.10 | nats-server | No fix yet | — |
| Ubuntu 24.04 LTS | nats-server | No fix yet | — |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 26.04 LTS | nats-server | No fix yet | — |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Leap 16.0 | govulncheck-vulndb | 0.0.20260723T184607-160000.1.1 | openSUSE-SU-2026:21483-1 |
| openSUSE Leap 15.6 | govulncheck-vulndb | 0.0.20260326T203309-150000.1.155.2 | SUSE-SU-2026:1135-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | nats-server | 2.12.6-r0 | — |
| Alpine v3.23 | nats-server | 2.12.6-r0 | — |
Wolfi
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Wolfi rolling | k3s +1 | 1.35.2.1-r4 | — |
| Wolfi rolling | k3s-1.32 +1 | 1.32.13.1-r7 | — |
| Wolfi rolling | kine | 0.14.15-r1 | — |
| Wolfi rolling | nats | 0.3.2-r0 | — |
| Wolfi rolling | nats-top | 0.6.3-r18 | — |
| Wolfi rolling | telegraf-1.38 | 1.38.1-r1 | — |
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| Go | github.com/nats-io/nats-server | all versions | — | GO-2026-4833 |
| Go | github.com/nats-io/nats-server/v2 | < 2.11.15 | 2.11.15 | GHSA-fcjp-h8cc-6879 |
| Go | github.com/nats-io/nats-server/v2 | >= 2.12.0-RC.1, < 2.12.6 | 2.12.6 | GHSA-fcjp-h8cc-6879 |
| Go | github.com/nats-io/nats-server/v2 | < 2.11.15 · >= 2.12.0-RC.1, < 2.12.6 | 2.11.15, 2.12.6 | GO-2026-4833 |
Advisories 3
- openSUSE-SU-2026:21483-1 Security update for govulncheck-vulndb SUSE / openSUSE Security Updates · Jul 31, 2026
- WID-SEC-2026-0858 NATS Server: Mehrere Schwachstellen BSI CERT-Bund (WID) · Jun 1, 2026
- SUSE-SU-2026:1135-1 Security update for govulncheck-vulndb SUSE / openSUSE Security Updates · Mar 31, 2026