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nats-server — security advisory

Type: advisorySources: OSVAdvisory ID: UBUNTU-CVE-2026-33215

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.

Products
nats-server
Affected versions
2.10.24-1, 2.10.27-1, 2.10.27-1build1, 2.10.27-1ubuntu0.26.04.1~esm1, 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, 2.14.1-1, 2.14.3-1, 2.9.19-1build1
Fixed versions
Not specified
CVEs
CVE-2026-33215
Confirmed fixed CVEs
Not specified
Updated in this feed
31 Oct 2026, 02:59 UTC · Revision 1

Source evidence

UBUNTU-CVE-2026-33215

core-osv · Original source

Published 24 Mar 2026, 21:16 UTC

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.

osv:UBUNTU-CVE-2026-33215

nats-server

Fixed versions: Not specified

nats-server

Fixed versions: Not specified

nats-server

Fixed versions: Not specified

nats-server

Fixed versions: Not specified

Complete source record
{
  "id": "9cb2205b8de2236e632ee161edbb2f155530a07d24331ced009af21eaf62b0bf",
  "url": "https://osv.dev/vulnerability/UBUNTU-CVE-2026-33215",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "UBUNTU-CVE-2026-33215",
    "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.",
    "evidence": "osv:UBUNTU-CVE-2026-33215",
    "products": [
      {
        "name": {
          "value": "nats-server",
          "evidence": "/affected/0/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": [
          {
            "value": "2.9.19-1build1",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "2.10.3-1",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "2.10.4-1",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "2.10.7-1",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "2.10.7-1ubuntu0.1",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "2.10.7-1ubuntu0.2",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "2.10.7-1ubuntu0.3",
            "evidence": "/affected/0/versions"
          }
        ]
      },
      {
        "name": {
          "value": "nats-server",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": [
          {
            "value": "2.10.24-1",
            "evidence": "/affected/1/versions"
          },
          {
            "value": "2.10.27-1",
            "evidence": "/affected/1/versions"
          }
        ]
      },
      {
        "name": {
          "value": "nats-server",
          "evidence": "/affected/2/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": [
          {
            "value": "2.10.27-1build1",
            "evidence": "/affected/2/versions"
          },
          {
            "value": "2.14.1-1",
            "evidence": "/affected/2/versions"
          },
          {
            "value": "2.14.3-1",
            "evidence": "/affected/2/versions"
          }
        ]
      },
      {
        "name": {
          "value": "nats-server",
          "evidence": "/affected/3/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": [
          {
            "value": "2.10.27-1",
            "evidence": "/affected/3/versions"
          },
          {
            "value": "2.10.27-1build1",
            "evidence": "/affected/3/versions"
          },
          {
            "value": "2.10.27-1ubuntu0.26.04.1~esm1",
            "evidence": "/affected/3/versions"
          }
        ]
      }
    ],
    "severity": "medium",
    "structured": {
      "id": "UBUNTU-CVE-2026-33215",
      "aliases": [
        "UBUNTU-CVE-2026-33215"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "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": "Ubuntu",
          "score": "medium"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                }
              ]
            }
          ],
          "package": {
            "name": "nats-server",
            "purl": "pkg:deb/ubuntu/nats-server?arch=source&distro=noble",
            "ecosystem": "Ubuntu:24.04:LTS"
          },
          "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"
          ],
          "database_specific": {
            "source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-33215.json"
          },
          "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"
              }
            ]
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                }
              ]
            }
          ],
          "package": {
            "name": "nats-server",
            "purl": "pkg:deb/ubuntu/nats-server?arch=source&distro=questing",
            "ecosystem": "Ubuntu:25.10"
          },
          "versions": [
            "2.10.24-1",
            "2.10.27-1"
          ],
          "database_specific": {
            "source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-33215.json"
          },
          "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"
              }
            ]
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                }
              ]
            }
          ],
          "package": {
            "name": "nats-server",
            "purl": "pkg:deb/ubuntu/nats-server?arch=source&distro=stonking",
            "ecosystem": "Ubuntu:26.10"
          },
          "versions": [
            "2.10.27-1build1",
            "2.14.1-1",
            "2.14.3-1"
          ],
          "database_specific": {
            "source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-33215.json"
          },
          "ecosystem_specific": {
            "binaries": [
              {
                "binary_name": "golang-github-nats-io-nats-server-dev",
                "binary_version": "2.14.3-1"
              },
              {
                "binary_name": "nats-server",
                "binary_version": "2.14.3-1"
              }
            ]
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                }
              ]
            }
          ],
          "package": {
            "name": "nats-server",
            "purl": "pkg:deb/ubuntu/nats-server?arch=source&distro=esm-apps%2Fresolute",
            "ecosystem": "Ubuntu:Pro:26.04:LTS"
          },
          "versions": [
            "2.10.27-1",
            "2.10.27-1build1",
            "2.10.27-1ubuntu0.26.04.1~esm1"
          ],
          "database_specific": {
            "source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-33215.json"
          },
          "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"
              }
            ]
          }
        }
      ],
      "modified": "2026-10-17T13:00:00.412329352Z",
      "provider": "osv",
      "upstream": [
        "CVE-2026-33215"
      ],
      "references": [
        "https://ubuntu.com/security/CVE-2026-33215",
        "https://www.cve.org/CVERecord?id=CVE-2026-33215",
        "https://github.com/nats-io/nats-server/security/advisories/GHSA-fcjp-h8cc-6879",
        "https://advisories.nats.io/CVE/secnote-2026-06.txt",
        "https://advisories.nats.io/CVE/secnote-2026-06.tx"
      ]
    },
    "related_cves": [
      {
        "value": "CVE-2026-33215",
        "evidence": "/upstream"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 360099,
  "published_at": "2026-03-24T21:16:00+00:00"
}