ubuntu-cve-2026-33219
Vulnerability from osv_ubuntu
Published
2026-03-25 20:16
Modified
2026-07-02 16:13
Summary
Details

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, a malicious client which can connect to the WebSockets port can cause unbounded memory use in the nats-server before authentication; this requires sending a corresponding amount of data. This is a milder variant of CVE-2026-27571. That earlier issue was a compression bomb, this vulnerability is not. Attacks against this new issue thus require significant client bandwidth. Versions 2.11.15 and 2.12.6 contain a fix. As a workaround, disable websockets if not required for project deployment.

Severity
5.3 (Medium)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
7.5 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
N/A (UNKNOWN)
medium
References
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. Prior to versions 2.11.15 and 2.12.6, a malicious client which can connect to the WebSockets port can cause unbounded memory use in the nats-server before authentication; this requires sending a corresponding amount of data. This is a milder variant of CVE-2026-27571. That earlier issue was a compression bomb, this vulnerability is not. Attacks against this new issue thus require significant client bandwidth. Versions 2.11.15 and 2.12.6 contain a fix. As a workaround, disable websockets if not required for project deployment.",
  "id": "UBUNTU-CVE-2026-33219",
  "modified": "2026-07-02T16:13:27Z",
  "published": "2026-03-25T20:16:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-33219"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-33219"
    },
    {
      "type": "REPORT",
      "url": "https://advisories.nats.io/CVE/secnote-2026-02.txt"
    },
    {
      "type": "REPORT",
      "url": "https://advisories.nats.io/CVE/secnote-2026-11.txt"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/advisories/GHSA-qrvq-68c2-7grw"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/nats-io/nats-server/security/advisories/GHSA-8r68-gvr4-jh7j"
    }
  ],
  "related": [],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2026-33219"
  ]
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

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.