Vulnerability-Lookup

CVE-2026-33215 (GCVE-0-2026-33215)

Vulnerability from cvelistv5 – Published: 2026-03-24 20:55 – Updated: 2026-03-25 13:05

Title

NATS is vulnerable to MQTT hijacking via Client ID

Summary

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.

Severity

6.5 (Medium)


                        
                          CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:L

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-03-25 13:03 UTC

CWE

CWE-287 - Improper Authentication
CWE-488 - Exposure of Data Element to Wrong Session

Assigner

GitHub_M mitre root

References

2 references

URL	Tags
https://github.com/nats-io/nats-server/security/a…	x_refsource_CONFIRM
https://advisories.nats.io/CVE/secnote-2026-06.tx	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version	CPE status
nats-io	nats-server	Affected: < 2.11.15 Affected: >= 2.12.0-RC.1, < 2.12.6	guessed

Show details on NVD website

JSON

To clipboard

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                "id": "CVE-2026-33215",
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}

bit-nats-2026-33215

Vulnerability from bitnami_vulndb

Published

2026-03-27 07:08

Modified

2026-09-08 08:34

Summary

NATS is vulnerable to MQTT hijacking via Client ID

Details

JSON

To clipboard

{
  "affected": [
    {
      "package": {
        "ecosystem": "Bitnami",
        "name": "nats",
        "purl": "pkg:bitnami/nats"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "2.11.15"
            },
            {
              "introduced": "2.12.0"
            },
            {
              "fixed": "2.12.6"
            }
          ],
          "type": "SEMVER"
        }
      ],
      "severity": [
        {
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N",
          "type": "CVSS_V3"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-33215"
  ],
  "database_specific": {
    "cpes": [
      "cpe:2.3:a:nats:nats_server:*:*:*:*:*:go:*:*"
    ],
    "severity": "Medium"
  },
  "details": "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.",
  "id": "BIT-nats-2026-33215",
  "modified": "2026-09-08T08:34:36.952Z",
  "published": "2026-03-27T07:08:53.339Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://advisories.nats.io/CVE/secnote-2026-06.tx"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/nats-io/nats-server/security/advisories/GHSA-fcjp-h8cc-6879"
    },
    {
      "type": "WEB",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-33215"
    }
  ],
  "schema_version": "1.6.2",
  "summary": "NATS is vulnerable to MQTT hijacking via Client ID"
}

FKIE_CVE-2026-33215

Vulnerability from fkie_nvd - Published: 2026-03-24 21:16 - Updated: 2026-06-17 10:37

Severity

6.5 (Medium) - CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:L
6.5 (Medium) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

Summary

References

	URL	Tags
	security-advisories@github.com	https://advisories.nats.io/CVE/secnote-2026-06.tx	Broken Link
	security-advisories@github.com	https://github.com/nats-io/nats-server/security/advisories/GHSA-fcjp-h8cc-6879	Vendor Advisory

Impacted products

	Vendor	Product	Version
	linuxfoundation	nats-server	*
	linuxfoundation	nats-server	*

JSON

To clipboard

{
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    {
      "affectedData": [
        {
          "product": "nats-server",
          "vendor": "nats-io",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 2.11.15"
            },
            {
              "status": "affected",
              "version": "\u003e= 2.12.0-RC.1, \u003c 2.12.6"
            }
          ]
        }
      ],
      "source": "security-advisories@github.com"
    }
  ],
  "configurations": [
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              "versionEndExcluding": "2.11.15",
              "versionStartIncluding": "2.0.0",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:a:linuxfoundation:nats-server:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "B141DA72-3502-4746-A246-EE1087C993F4",
              "versionEndExcluding": "2.12.5",
              "versionStartIncluding": "2.12.0",
              "vulnerable": true
            }
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    },
    {
      "lang": "es",
      "value": "NATS-Server es un servidor de alto rendimiento para NATS.io, un sistema de mensajer\u00eda nativo de la nube y del borde. El nats-server proporciona una interfaz de cliente MQTT. Antes de las versiones 2.11.15 y 2.12.5, las sesiones y los mensajes pueden ser secuestrados mediante la malversaci\u00f3n del ID de cliente MQTT. Las versiones 2.11.15 y 2.12.5 parchean el problema. No hay soluciones alternativas conocidas disponibles."
    }
  ],
  "id": "CVE-2026-33215",
  "lastModified": "2026-06-17T10:37:08.227",
  "metrics": {
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          "attackComplexity": "HIGH",
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          "baseScore": 6.5,
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          "confidentialityImpact": "HIGH",
          "integrityImpact": "NONE",
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          "confidentialityImpact": "LOW",
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        "source": "nvd@nist.gov",
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      ],
      "url": "https://advisories.nats.io/CVE/secnote-2026-06.tx"
    },
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    }
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}

GHSA-FCJP-H8CC-6879

Vulnerability from github – Published: 2026-03-24 21:39 – Updated: 2026-03-27 20:55

Summary

NATS is vulnerable to MQTT hijacking via Client ID

Details

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 nats-server provides an MQTT client interface.

Problem Description

Sessions and Messages can by hijacked via MQTT Client ID malfeasance.

Affected Versions

Any version before v2.12.6 or v2.11.15

Workarounds

None.

Resources

This document is canonically: https://advisories.nats.io/CVE/secnote-2026-06.txt
GHSA advisory: https://github.com/nats-io/nats-server/security/advisories/GHSA-fcjp-h8cc-6879
MITRE CVE entry: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2026-33215

Severity

6.5 (Medium)


                  
                    CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:L

Show details on source website

JSON

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{
  "affected": [
    {
      "package": {
        "ecosystem": "Go",
        "name": "github.com/nats-io/nats-server/v2"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "2.11.15"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Go",
        "name": "github.com/nats-io/nats-server/v2"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "2.12.0-RC.1"
            },
            {
              "fixed": "2.12.6"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-33215"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-287"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-03-24T21:39:52Z",
    "nvd_published_at": "2026-03-24T21:16:28Z",
    "severity": "MODERATE"
  },
  "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 nats-server provides an MQTT client interface.\n\n### Problem Description\n\nSessions and Messages can by hijacked via MQTT Client ID malfeasance.\n\n### Affected Versions\n\nAny version before v2.12.6 or v2.11.15\n\n### Workarounds\n\nNone.\n\n### Resources\n\n * This document is canonically: \u003chttps://advisories.nats.io/CVE/secnote-2026-06.txt\u003e\n * GHSA advisory: \u003chttps://github.com/nats-io/nats-server/security/advisories/GHSA-fcjp-h8cc-6879\u003e\n * MITRE CVE entry: \u003chttps://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2026-33215\u003e",
  "id": "GHSA-fcjp-h8cc-6879",
  "modified": "2026-03-27T20:55:01Z",
  "published": "2026-03-24T21:39:52Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/nats-io/nats-server/security/advisories/GHSA-fcjp-h8cc-6879"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-33215"
    },
    {
      "type": "WEB",
      "url": "https://advisories.nats.io/CVE/secnote-2026-06.tx"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/nats-io/nats-server"
    },
    {
      "type": "WEB",
      "url": "https://pkg.go.dev/vuln/GO-2026-4833"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:L",
      "type": "CVSS_V3"
    }
  ],
  "summary": "NATS is vulnerable to MQTT hijacking via Client ID"
}

RHSA-2026:21769

Vulnerability from csaf_redhat - Published: 2026-05-28 20:39 - Updated: 2026-09-14 15:15

Summary

Red Hat Security Advisory: Multicluster Global Hub 1.5.4 security update

Severity

Important

Scope

35 vulnerabilities in this advisory, including CVE-2026-33215.

CVE-2026-33215

A flaw was found in NATS-Server. A remote attacker could exploit this vulnerability by manipulating MQTT (Message Queuing Telemetry Transport) Client IDs. This malfeasance allows for the hijacking of client sessions and messages. This could lead to unauthorized access to sensitive information or disruption of service.

6.5 (Medium)


                
                  CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:L

Fixed: 4 products Known not affected: 17 products

https://access.redhat.com/errata/RHSA-2026:21769

Open the full advisory

RHSA-2026:22347

Vulnerability from csaf_redhat - Published: 2026-06-01 22:12 - Updated: 2026-09-14 15:15

Summary

Red Hat Security Advisory: Multicluster Global Hub 1.4.5 security update

Severity

Important

Scope

35 vulnerabilities in this advisory, including CVE-2026-33215.

CVE-2026-33215

6.5 (Medium)


                
                  CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:L

Fixed: 4 products Known not affected: 17 products

https://access.redhat.com/errata/RHSA-2026:22347

Open the full advisory

RHSA-2026:23345

Vulnerability from csaf_redhat - Published: 2026-06-04 14:16 - Updated: 2026-09-14 15:16

Summary

Red Hat Security Advisory: Multicluster Global Hub 1.6.2 security update

Severity

Important

Scope

35 vulnerabilities in this advisory, including CVE-2026-33215.

CVE-2026-33215

6.5 (Medium)


                
                  CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:L

Fixed: 4 products Known not affected: 17 products

https://access.redhat.com/errata/RHSA-2026:23345

Open the full advisory

ubuntu-cve-2026-33215

Vulnerability from osv_ubuntu

Published

2026-03-24 21:16

Modified

2026-07-02 16:13

Summary

Details

Severity

6.5 (Medium)


                    
                      CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:L

6.5 (Medium)


                    
                      CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

N/A (UNKNOWN)


                    
                      medium

References

URL

Type

	https://ubuntu.com/security/CVE-2026-33215	REPORT
	https://www.cve.org/CVERecord?id=CVE-2026-33215	REPORT
	https://github.com/nats-io/nats-server/security/a…	REPORT
	https://advisories.nats.io/CVE/secnote-2026-06.txt	REPORT
	https://advisories.nats.io/CVE/secnote-2026-06.tx	REPORT

JSON

To clipboard

{
  "affected": [
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "golang-github-nats-io-nats-server-dev",
            "binary_version": "2.10.7-1ubuntu0.3"
          },
          {
            "binary_name": "nats-server",
            "binary_version": "2.10.7-1ubuntu0.3"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:24.04:LTS",
        "name": "nats-server",
        "purl": "pkg:deb/ubuntu/nats-server@2.10.7-1ubuntu0.3?arch=source\u0026distro=noble"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "2.9.19-1build1",
        "2.10.3-1",
        "2.10.4-1",
        "2.10.7-1",
        "2.10.7-1ubuntu0.1",
        "2.10.7-1ubuntu0.2",
        "2.10.7-1ubuntu0.3"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "golang-github-nats-io-nats-server-dev",
            "binary_version": "2.10.27-1"
          },
          {
            "binary_name": "nats-server",
            "binary_version": "2.10.27-1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:25.10",
        "name": "nats-server",
        "purl": "pkg:deb/ubuntu/nats-server@2.10.27-1?arch=source\u0026distro=questing"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "2.10.24-1",
        "2.10.27-1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "golang-github-nats-io-nats-server-dev",
            "binary_version": "2.10.27-1ubuntu0.26.04.1~esm1"
          },
          {
            "binary_name": "nats-server",
            "binary_version": "2.10.27-1ubuntu0.26.04.1~esm1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:26.04:LTS",
        "name": "nats-server",
        "purl": "pkg:deb/ubuntu/nats-server@2.10.27-1ubuntu0.26.04.1~esm1?arch=source\u0026distro=esm-apps/resolute"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "2.10.27-1",
        "2.10.27-1build1",
        "2.10.27-1ubuntu0.26.04.1~esm1"
      ]
    }
  ],
  "aliases": [],
  "details": "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.",
  "id": "UBUNTU-CVE-2026-33215",
  "modified": "2026-07-02T16:13:27Z",
  "published": "2026-03-24T21:16:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-33215"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-33215"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/nats-io/nats-server/security/advisories/GHSA-fcjp-h8cc-6879"
    },
    {
      "type": "REPORT",
      "url": "https://advisories.nats.io/CVE/secnote-2026-06.txt"
    },
    {
      "type": "REPORT",
      "url": "https://advisories.nats.io/CVE/secnote-2026-06.tx"
    }
  ],
  "related": [],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:L",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N",
      "type": "CVSS_V3"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2026-33215"
  ]
}

WID-SEC-W-2026-0858

Vulnerability from csaf_certbund - Published: 2026-03-24 23:00 - Updated: 2026-06-01 22:00

Summary

NATS Server: Mehrere Schwachstellen

Severity

Hoch

Scope

11 vulnerabilities in this advisory, including CVE-2026-33215.

CVE-2026-33215

Known affected: 3 products

Open the full advisory

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.

Action not permitted

CVE-2026-33215 (GCVE-0-2026-33215)

Vulnerability from bitnami_vulndb

Background

Problem Description

Affected Versions

Workarounds

Resources

Vulnerability from osv_ubuntu

Tags

Sightings

Nomenclature