CVE-2026-33222: Github.com/nats io/nats server/v2 NATS JetStream Has An Authorization Vulnerability

MODERATE
Advisory Identifier: GHSA-9983-vrx2-fg9c
CVSS 4.9
CWE-285
Published
Advisory Summary

CVE-2026-33222 is a MODERATE (CVSS 4.9) nats jetstream has an authorization vulnerability (CWE-285: Improper Authorization) affecting Github.com/nats io/nats server/v2 libraries in the Go ecosystem. The issue involves nats jetstream has an authorization bypass through its management api. Remediation is available by upgrading affected packages to version 2.11.15, 2.12.6.

CVE-2026-33222 at a Glance

CVE Identifier CVE-2026-33222
GHSA Identifier GHSA-9983-vrx2-fg9c
Severity MODERATE
CVSS v3.1 Base Score 4.9
CWE Classification CWE-285: Improper Authorization
Affected Product Github.com/nats io/nats server/v2
Package Ecosystem Go
Published Date
Last Updated

Security Impact

CVSS: 4.9

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:N).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required High (PR:H)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality None (C:N)
Integrity High (I:H)
Availability None (A:N)

How to Fix CVE-2026-33222

To remediate this vulnerability, upgrade all affected Github.com/nats io/nats server/v2 dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

github.com/nats-io/nats-server/v2 fixed: 2.11.15
Upgrade github.com/nats-io/nats-server/v2 to 2.11.15
github.com/nats-io/nats-server/v2 fixed: 2.12.6
Upgrade github.com/nats-io/nats-server/v2 to 2.12.6
github.com/nats-io/nats-server fixed: Latest secure release
Upgrade github.com/nats-io/nats-server to Latest secure release
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release:

inspect dependencies for github.com/nats-io/nats-server/v2

How to Check if You Are Affected

To determine whether your application is affected by CVE-2026-33222, inspect your project dependencies for Github.com/nats io/nats server/v2:

inspect dependencies for github.com/nats-io/nats-server/v2

Analyze the terminal output to locate any version of Github.com/nats io/nats server/v2 in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 2.11.15), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-285: Improper Authorization, where the product does not perform or incorrectly performs an authorization check when an actor attempts to access a resource or perform an action. In Github.com/nats io/nats server/v2, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

### Background NATS.io is a high performance open source pub-sub distributed communication technology, built for the cloud, on-premise, IoT, and edge computing. The persistent storage feature, JetStream, has a management API which has many features, amongst which are backup and restore. ### Problem Description Users with JetStream admin API access to restore one stream could restore to other stream names, impacting data which should have been protected against them. ### Affected Versions Any version before v2.12.6 or v2.11.15 ### Workarounds If developers have configured users to have limited JetStream restore permissions, temporarily remove those permissions.

CVE-2026-33222 Affected Github.com/nats io/nats server/v2 Versions

3 component(s)
Fixed Versions:
2.11.152.12.6
Product / Package Ecosystem Affected Versions Fixed Version
github.com/nats-io/nats-server/v2
Go
< 2.11.15
2.11.15
github.com/nats-io/nats-server/v2
Go
≥ 2.12.0-RC.1
< 2.12.6
2.12.6
github.com/nats-io/nats-server
Go

References

Frequently Asked Questions

What is CVE-2026-33222?
CVE-2026-33222 is a security vulnerability in Github.com/nats io/nats server/v2 involving NATS JetStream has an authorization bypass through its Management API under CWE-285: Improper Authorization.
Which Github.com/nats io/nats server/v2 versions are affected?
Affected versions include releases prior to 2.11.15, 2.12.6 across affected packages: github.com/nats-io/nats-server/v2, github.com/nats-io/nats-server.
What version fixes CVE-2026-33222?
Upgrading to 2.11.15, 2.12.6 (or the latest patched release for your respective branch) resolves the vulnerability.
Is github.com/nats-io/nats-server/v2 affected?
Yes, github.com/nats-io/nats-server/v2 is affected in releases prior to 2.11.15, 2.12.6. Upgrade your dependency to 2.11.15, 2.12.6 or later.
Is github.com/nats-io/nats-server affected?
Yes, github.com/nats-io/nats-server is affected in releases prior to Latest secure release. Upgrade your dependency to Latest secure release or later.
What is the CVSS score of CVE-2026-33222?
CVE-2026-33222 has a CVSS v3.1 base score of 4.9 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:N.
What CWE is associated with CVE-2026-33222?
CVE-2026-33222 is classified under CWE-285: Improper Authorization (The product does not perform or incorrectly performs an authorization check when an actor attempts to access a resource or perform an action.).
How can I check Go dependencies for CVE-2026-33222?
Run the dependency tree command: 'inspect dependencies for github.com/nats-io/nats-server/v2'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-9983-vrx2-fg9c",
  "modified" : "2026-03-27T22:10:15Z",
  "published" : "2026-03-24T21:49:34Z",
  "aliases" : [ "CVE-2026-33222" ],
  "summary" : "NATS JetStream has an authorization bypass through its Management API",
  "details" : "### Background\n\nNATS.io is a high performance open source pub-sub distributed communication technology, built for the cloud, on-premise, IoT, and edge computing.\n\nThe persistent storage feature, JetStream, has a management API which has many features, amongst which are backup and restore.\n\n### Problem Description\n\nUsers with JetStream admin API access to restore one stream could restore to other stream names, impacting data which should have been protected against them.\n\n### Affected Versions\n\nAny version before v2.12.6 or v2.11.15\n\n### Workarounds\n\nIf developers have configured users to have limited JetStream restore permissions, temporarily remove those permissions.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/nats-io/nats-server/v2"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "2.11.15"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/nats-io/nats-server/v2"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "2.12.0-RC.1"
      }, {
        "fixed" : "2.12.6"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/nats-io/nats-server"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/nats-io/nats-server/security/advisories/GHSA-9983-vrx2-fg9c"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-33222"
  }, {
    "type" : "WEB",
    "url" : "https://advisories.nats.io/CVE/secnote-2026-12.txt"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/nats-io/nats-server"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-285" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-03-24T21:49:34Z",
    "nvd_published_at" : "2026-03-25T21:16:47Z"
  }
}