CVE catalog

CVE-2026-33217

NATS-Server is a High-Performance server for NATS.io…

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, when using ACLs on message subjects, these ACLs were not applied in the `$MQTT.>` namespace, allowing MQTT clients to bypass ACL checks for MQTT subjects. Versions 2.11.15 and 2.12.6 contain a fix. No known workarounds are available.

Severity: High · CVSS 8.1CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
Published: Mar 24, 2026, 11:00:00 PM UTC
Source: [NVD] · [CVE record]
EPSS: 0.26% · Oct 27, 2026

Projects and upstream resources

[nats-server][Source-reported homepage]

Reported versions and fixes

Each observation applies to its named package, distribution, and release. Distribution backports can fix a vulnerability while retaining an older upstream version number.

Distribution / release	Package	Version	Status	Source
Debiansid	nats-server	`2.12.6-1`	FixedDistribution-reported fixed boundary	[CVE-2026-33217]
Debiansid	nats-server	`2.15.1-1`	Fixed	[CVE-2026-33217]
Debianforky	nats-server	`2.12.6-1`	FixedDistribution-reported fixed boundary	[CVE-2026-33217]
Debianforky	nats-server	`2.15.1-1`	Fixed	[CVE-2026-33217]

Showing 4 fix observations. All 13 observations, including unknown and conflicting reports, are available below.

Provider details and historical evidence

Distribution / release	Package	Version	Status	Source
GoRelease not reported	github.com/nats-io/nats-server/v2	`2.11.15`	UnknownSource applicability is not established	Provider not reported
GoRelease not reported	github.com/nats-io/nats-server/v2	`2.12.6`	UnknownSource applicability is not established	Provider not reported
UnknownRelease not reported	nats-server	Not reported	UnknownSource applicability is not established	Provider not reported
UnknownRelease not reported	nats-server	`2.11.15`	UnknownSource applicability is not established	Provider not reported
UnknownRelease not reported	nats-server	`2.12.6`	UnknownSource applicability is not established	Provider not reported
Debianbookworm	nats-server	Not reported	AffectedDistribution reports no fix	[CVE-2026-33217]
Debianbookworm	nats-server	`2.9.10-1`	Affected	[CVE-2026-33217]
Debianforky	nats-server	`2.12.6-1`	FixedDistribution-reported fixed boundary	[CVE-2026-33217]
Debianforky	nats-server	`2.15.1-1`	Fixed	[CVE-2026-33217]
Debiansid	nats-server	`2.12.6-1`	FixedDistribution-reported fixed boundary	[CVE-2026-33217]
Debiansid	nats-server	`2.15.1-1`	Fixed	[CVE-2026-33217]
Debiantrixie	nats-server	Not reported	AffectedDistribution reports no fix	[CVE-2026-33217]
Debiantrixie	nats-server	`2.10.27-1`	Affected	[CVE-2026-33217]

Original provider fields

{
  "package_releases": [
    {
      "name": "nats-server",
      "status": "fixed",
      "release": "sid",
      "version": "2.15.1-1"
    },
    {
      "name": "nats-server",
      "status": "fixed",
      "release": "forky",
      "version": "2.15.1-1"
    },
    {
      "name": "nats-server",
      "status": "vulnerable",
      "release": "trixie",
      "version": "2.10.27-1"
    },
    {
      "name": "nats-server",
      "status": "vulnerable",
      "release": "bookworm",
      "version": "2.9.10-1"
    }
  ],
  "fixed_versions": [
    {
      "bug": null,
      "name": "nats-server",
      "type": "source",
      "origin": null,
      "release": "sid",
      "urgency": "not yet assigned",
      "fixed_version": "2.12.6-1"
    },
    {
      "bug": null,
      "name": "nats-server",
      "type": "source",
      "origin": null,
      "release": "forky",
      "urgency": "not yet assigned",
      "fixed_version": "2.12.6-1"
    },
    {
      "bug": null,
      "name": "nats-server",
      "type": "source",
      "origin": null,
      "release": "trixie",
      "urgency": "not yet assigned",
      "fixed_version": ""
    },
    {
      "bug": null,
      "name": "nats-server",
      "type": "source",
      "origin": null,
      "release": "bookworm",
      "urgency": "not yet assigned",
      "fixed_version": ""
    }
  ],
  "distribution_packages": [
    {
      "name": "github.com/nats-io/nats-server/v2",
      "ecosystem": "go",
      "fixed_version": "2.11.15",
      "applicability_unknown": true
    },
    {
      "name": "github.com/nats-io/nats-server/v2",
      "ecosystem": "go",
      "fixed_version": "2.12.6",
      "applicability_unknown": true
    },
    {
      "name": "nats-server",
      "fixed_version": "not yet fixed",
      "applicability_unknown": true
    },
    {
      "name": "nats-server",
      "fixed_version": "2.11.15",
      "applicability_unknown": true
    },
    {
      "name": "nats-server",
      "fixed_version": "2.12.6",
      "applicability_unknown": true
    },
    {
      "name": "nats-server",
      "ranges": [
        {
          "fixed": "2.12.6",
          "introduced": "2.12.0",
          "last_affected": "",
          "start_excluding": ""
        }
      ],
      "ecosystem": "cpe",
      "provider_url": "https://nvd.nist.gov/vuln/detail/CVE-2026-33217",
      "fixed_version": "2.12.6",
      "provider_source": "nvd",
      "provider_record_id": "NVD-CVE-2026-33217",
      "provider_updated_at": "2026-09-09T13:19:23.763"
    }
  ]
}

OpenFactory catalog packages

Matching against OpenFactory catalog package versions is in progress.

[Debian 12 (Bookworm)]

[golang-github-nats-io-nats-server-dev]Unknown
Source package: [nats-server]
Details (2)
- 2.9.10-1 · all · bookworm
  Affected
  nvd · nats-server · debian · bookworm; nvd · nats-server · debian · 12
- 2.9.10-1 · all · bookworm
  Affected
  nvd · nats-server · debian · bookworm; nvd · nats-server · debian · 12
[nats-server]Unknown
Source package: [nats-server]
Details (2)
- 2.9.10-1+b3 · amd64 · bookworm
  Affected
  nvd · nats-server · debian · bookworm; nvd · nats-server · debian · 12
- 2.9.10-1+b3 · arm64 · bookworm
  Affected
  nvd · nats-server · debian · bookworm; nvd · nats-server · debian · 12

[Debian 13 (Trixie)]

[golang-github-nats-io-nats-server-dev]Unknown
Source package: [nats-server]
Details (2)
- 2.10.27-1 · all · trixie
  Affected
  nvd · nats-server · debian · 13
- 2.10.27-1 · all · trixie
  Affected
  nvd · nats-server · debian · 13
[nats-server]Unknown
Source package: [nats-server]
Details (2)
- 2.10.27-1+b2 · amd64 · trixie
  Affected
  nvd · nats-server · debian · 13
- 2.10.27-1+b2 · arm64 · trixie
  Affected
  nvd · nats-server · debian · 13

Observed: Oct 23, 2026, 10:39:00 PM UTC

References

[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]