CVE catalog
CVE-2026-58253
NATS Server is a high-performance server for NATS.io, the cloud and edge native messaging system. Prior to 2.14.0, 2.12.7, and 2.11.16, when no_auth_user was configured, a parser fast path intended fo
- Severity
- High · CVSS 8.8
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:L/I:H/A:L - Published
- Source
- [NVD] · [CVE record]
- EPSS
- 0.37% · Oct 25, 2026
NATS Server is a high-performance server for NATS.io, the cloud and edge native messaging system. Prior to 2.14.0, 2.12.7, and 2.11.16, when no_auth_user was configured, a parser fast path intended for ordinary client connections could also apply to route or leafnode listeners, allowing an unauthenticated peer to bypass inter-server CONNECT authentication and operate with the privileges associated with that connection type. This issue is fixed in versions 2.14.0, 2.12.7, and 2.11.16.
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 |
| Cpe | nats-server | Not reported | Not reported | vulnerable |
| Ubuntu | nats-server | 24.04 | 2.9.19-1build1 | vulnerable |
| Ubuntu | nats-server | 24.04 | 2.10.3-1 | vulnerable |
| Ubuntu | nats-server | 24.04 | 2.10.4-1 | vulnerable |
| Ubuntu | nats-server | 24.04 | 2.10.7-1 | vulnerable |
| Ubuntu | nats-server | 24.04 | 2.10.7-1ubuntu0.1 | vulnerable |
| Ubuntu | nats-server | 24.04 | 2.10.7-1ubuntu0.2 | vulnerable |
| Ubuntu | nats-server | 24.04 | 2.10.7-1ubuntu0.3 | vulnerable |
| Ubuntu | nats-server | 25.10 | 2.10.24-1 | vulnerable |
| Ubuntu | nats-server | 25.10 | 2.10.27-1 | vulnerable |
| Ubuntu | nats-server | pro | 2.10.27-1 | vulnerable |
| Ubuntu | nats-server | pro | 2.10.27-1build1 | vulnerable |
| Ubuntu | nats-server | pro | 2.10.27-1ubuntu0.26.04.1~esm1 | vulnerable |
| Cpe | nats-server | Not reported | 2.12.7 | fixed |
Fixed-version evidence
| Distribution | Package | Type | Release | Fixed version | Urgency | Origin | Bugs |
|---|---|---|---|---|---|---|---|
| Debian | nats-server | source | sid | 2.14.1-1 | not yet assigned | Not reported | Not reported |
| Debian | nats-server | source | forky | 2.14.1-1 | 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 |
| Cpe | nats-server | cpe | Not reported | 2.12.7 | Not reported | NVD-CVE-2026-58253 | 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/nats-io/nats-server/commit/7b81dd455ea95960090a84858c7662827948d1b6]
- [https://github.com/nats-io/nats-server/commit/8b8e1ad4ceed32321e00d4fc6e76be05bc13bca6]
- [https://github.com/nats-io/nats-server/commit/b86147e81710a52b72a7f7275f91d69f723f5cb3]
- [https://github.com/nats-io/nats-server/releases/tag/v2.11.16]
- [https://github.com/nats-io/nats-server/releases/tag/v2.12.7]
- [https://github.com/nats-io/nats-server/releases/tag/v2.14.0]
- [https://github.com/nats-io/nats-server/security/advisories/GHSA-38x3-76xf-cq45]
- [https://nvd.nist.gov/vuln/detail/CVE-2026-58253]
- [https://osv.dev/vulnerability/DEBIAN-CVE-2026-58253]
- [https://osv.dev/vulnerability/UBUNTU-CVE-2026-58253]
- [https://security-tracker.debian.org/tracker/CVE-2026-58253]
- [https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-58253.json]
- [https://wid.cert-bund.de/.well-known/csaf/white/2026/wid-sec-w-2026-2132.json]
[CERT-Bund public advisories] · [Debian Security Tracker] · [FIRST EPSS] · [National Vulnerability Database (NVD)] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX]