CVE catalog
CVE-2026-33218
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
- Severity
- High · CVSS 7.5
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Published
- Source
- [NVD] · [CVE record]
- EPSS
- 0.63% · Oct 25, 2026
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.
Vulnerable and fixed packages
Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.
| Distribution | Package | Release | Version | Status |
|---|---|---|---|---|
| Debian | nats-server | sid | 2.15.1-1 | fixed |
| Debian | nats-server | forky | 2.15.1-1 | fixed |
| Debian | nats-server | trixie | 2.10.27-1 | vulnerable |
| Debian | nats-server | bookworm | 2.9.10-1 | vulnerable |
| Go | github.com/nats-io/nats-server/v2 | Not reported | 2.11.15 | fixed |
| Go | github.com/nats-io/nats-server/v2 | Not reported | 2.12.6 | fixed |
| Cpe | nats-server | Not reported | Not reported | vulnerable |
| Cpe | nats-server | Not reported | 2.11.15 | fixed |
| Cpe | nats-server | Not reported | 2.12.6 | fixed |
| Cpe | nats-server | Not reported | 2.12.6 | fixed |
Fixed-version evidence
| Distribution | Package | Type | Release | Fixed version | Urgency | Origin | Bugs |
|---|---|---|---|---|---|---|---|
| Debian | nats-server | source | sid | 2.12.6-1 | not yet assigned | Not reported | Not reported |
| Debian | nats-server | source | forky | 2.12.6-1 | not yet assigned | Not reported | Not reported |
| Debian | nats-server | source | trixie | (unfixed) | not yet assigned | Not reported | Not reported |
| Debian | nats-server | source | bookworm | (unfixed) | not yet assigned | Not reported | Not reported |
| Go | github.com/nats-io/nats-server/v2 | go | Not reported | 2.11.15 | Not reported | Not reported | Not reported |
| Go | github.com/nats-io/nats-server/v2 | go | Not reported | 2.12.6 | Not reported | Not reported | Not reported |
| Cpe | nats-server | cpe | Not reported | 2.11.15 | Not reported | Not reported | Not reported |
| Cpe | nats-server | cpe | Not reported | 2.12.6 | Not reported | Not reported | Not reported |
| Cpe | nats-server | cpe | Not reported | 2.12.6 | Not reported | NVD-CVE-2026-33218 | Not reported |
OpenFactory catalog packages
[Debian 12 (Bookworm)]
- [golang-github-nats-io-nats-server-dev]Affected
Source package: [nats-server]
Details (2)
2.9.10-1· all · bookwormAffected
nvd · nats-server · debian · bookworm; nvd · nats-server · debian · 12
2.9.10-1· all · bookwormAffected
nvd · nats-server · debian · bookworm; nvd · nats-server · debian · 12
- [nats-server]Affected
Source package: [nats-server]
Details (2)
2.9.10-1+b3· amd64 · bookwormAffected
nvd · nats-server · debian · bookworm; nvd · nats-server · debian · 12
2.9.10-1+b3· arm64 · bookwormAffected
nvd · nats-server · debian · bookworm; nvd · nats-server · debian · 12
[Debian 13 (Trixie)]
- [golang-github-nats-io-nats-server-dev]Affected
Source package: [nats-server]
Details (2)
2.10.27-1· all · trixieAffected
nvd · nats-server · debian · 13
2.10.27-1· all · trixieAffected
nvd · nats-server · debian · 13
- [nats-server]Affected
Source package: [nats-server]
Details (2)
2.10.27-1+b2· amd64 · trixieAffected
nvd · nats-server · debian · 13
2.10.27-1+b2· arm64 · trixieAffected
nvd · nats-server · debian · 13
Observed:
References
- [https://github.com/advisories/GHSA-vprv-35vv-q339]
- [https://nvd.nist.gov/vuln/detail/CVE-2026-33218]
- [https://osv.dev/vulnerability/DEBIAN-CVE-2026-33218]
- [https://security-tracker.debian.org/tracker/CVE-2026-33218]
- [https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-33218.json]
- [https://wid.cert-bund.de/.well-known/csaf/white/2026/wid-sec-w-2026-0858.json]
[CERT-Bund public advisories] · [Debian Security Tracker] · [FIRST EPSS] · [GitHub Advisory Database] · [National Vulnerability Database (NVD)] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX]