UBUNTU-CVE-2026-67240 (CVE-2026-67240)

Vulnerability from osv_ubuntu – Published: 2026-09-24 00:00 – Updated: 2026-09-24 00:00 – Source website
VLAI
Details

RabbitMQ is a messaging and streaming broker. Prior to versions 4.2.7 and 4.3.1, pattern_to_regex maps % -> .? and _ -> ., then compiles ^...$ with only [unicode]; re:run is called with only [{capture, none}] - no explicit match_limit. A pattern like %%..._%X becomes ^.?..?.....?.X$ with overlapping lazy quantifiers. The whole-expression cap is ?MAX_EXPRESSION_LENGTH=4096 chars / ?MAX_TOKENS=200; a LIKE string literal is one token, so ~2000 %_ pairs fit. SQL filters are accepted unconditionally at rabbit_amqp_session.erl:3264 (no feature flag). Evaluated per-message at rabbit_stream_queue.erl:1439. OTP's default 10M match_limit caps each match at ~100-200 ms (not seconds), and the re NIF yields to the scheduler. An authenticated AMQP 1.0 consumer with read+write on a stream queue can cause ~100-200 ms of CPU per delivered message via a crafted LIKE filter, multiplied across thousands of messages and parallel sessions - a substantial backtracking-driven CPU amplification. Preconditions include AMQP 1.0 with stream queues in use Attacker can attach a receiver with a filter (read permission) and publish messages with long property values (write permission). This issue is fixed in versions 4.2.7 and 4.3.1.

Severity
2.3 (Low)
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
N/A (UNKNOWN)
medium
References
To clipboard 

{
  "affected": [
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "rabbitmq-server",
            "binary_version": "3.5.7-1ubuntu0.16.04.4+esm2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:16.04:LTS",
        "name": "rabbitmq-server",
        "purl": "pkg:deb/ubuntu/rabbitmq-server@3.5.7-1ubuntu0.16.04.4+esm2?arch=source\u0026distro=esm-infra/xenial"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "3.5.4-1",
        "3.5.4-3",
        "3.5.4-3.1",
        "3.5.7-1",
        "3.5.7-1ubuntu0.16.04.1",
        "3.5.7-1ubuntu0.16.04.2",
        "3.5.7-1ubuntu0.16.04.4",
        "3.5.7-1ubuntu0.16.04.4+esm1",
        "3.5.7-1ubuntu0.16.04.4+esm2"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "rabbitmq-server",
            "binary_version": "3.6.10-1ubuntu0.5"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:18.04:LTS",
        "name": "rabbitmq-server",
        "purl": "pkg:deb/ubuntu/rabbitmq-server@3.6.10-1ubuntu0.5?arch=source\u0026distro=bionic"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "3.6.10-1",
        "3.6.10-1ubuntu0.1",
        "3.6.10-1ubuntu0.3",
        "3.6.10-1ubuntu0.4",
        "3.6.10-1ubuntu0.5"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "rabbitmq-server",
            "binary_version": "3.8.3-0ubuntu0.3"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:20.04:LTS",
        "name": "rabbitmq-server",
        "purl": "pkg:deb/ubuntu/rabbitmq-server@3.8.3-0ubuntu0.3?arch=source\u0026distro=focal"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "3.7.8-4ubuntu2",
        "3.7.18-1",
        "3.8.2-0ubuntu1",
        "3.8.2-0ubuntu1.1",
        "3.8.2-0ubuntu1.2",
        "3.8.2-0ubuntu1.3",
        "3.8.2-0ubuntu1.4",
        "3.8.2-0ubuntu1.5",
        "3.8.3-0ubuntu0.1",
        "3.8.3-0ubuntu0.2",
        "3.8.3-0ubuntu0.3"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "rabbitmq-server",
            "binary_version": "3.9.27-0ubuntu0.2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:22.04:LTS",
        "name": "rabbitmq-server",
        "purl": "pkg:deb/ubuntu/rabbitmq-server@3.9.27-0ubuntu0.2?arch=source\u0026distro=jammy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "3.8.9-3ubuntu1",
        "3.9.8-1",
        "3.9.8-2",
        "3.9.8-3",
        "3.9.8-5",
        "3.9.8-6",
        "3.9.13-1",
        "3.9.13-1ubuntu0.22.04.1",
        "3.9.13-1ubuntu0.22.04.2",
        "3.9.27-0ubuntu0.1",
        "3.9.27-0ubuntu0.2"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "rabbitmq-server",
            "binary_version": "3.12.1-1ubuntu1.4"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:24.04:LTS",
        "name": "rabbitmq-server",
        "purl": "pkg:deb/ubuntu/rabbitmq-server@3.12.1-1ubuntu1.4?arch=source\u0026distro=noble"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "3.12.1-1",
        "3.12.1-1ubuntu1",
        "3.12.1-1ubuntu1.2",
        "3.12.1-1ubuntu1.4"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "rabbitmq-server",
            "binary_version": "4.0.5-10ubuntu5"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:26.04:LTS",
        "name": "rabbitmq-server",
        "purl": "pkg:deb/ubuntu/rabbitmq-server@4.0.5-10ubuntu5?arch=source\u0026distro=resolute"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "4.0.5-8ubuntu2",
        "4.0.5-10ubuntu1",
        "4.0.5-10ubuntu2",
        "4.0.5-10ubuntu3",
        "4.0.5-10ubuntu4",
        "4.0.5-10ubuntu5"
      ]
    }
  ],
  "aliases": [],
  "details": "RabbitMQ is a messaging and streaming broker. Prior to versions 4.2.7 and 4.3.1, pattern_to_regex maps % -\u003e .*? and _ -\u003e ., then compiles ^...$ with only [unicode]; re:run is called with only [{capture, none}] - no explicit match_limit. A pattern like %_%_..._%X becomes ^.*?..*?.....*?.X$ with overlapping lazy quantifiers. The whole-expression cap is ?MAX_EXPRESSION_LENGTH=4096 chars / ?MAX_TOKENS=200; a LIKE string literal is one token, so ~2000 %_ pairs fit. SQL filters are accepted unconditionally at rabbit_amqp_session.erl:3264 (no feature flag). Evaluated per-message at rabbit_stream_queue.erl:1439. OTP\u0027s default 10M match_limit caps each match at ~100-200 ms (not seconds), and the re NIF yields to the scheduler. An authenticated AMQP 1.0 consumer with read+write on a stream queue can cause ~100-200 ms of CPU per delivered message via a crafted LIKE filter, multiplied across thousands of messages and parallel sessions - a substantial backtracking-driven CPU amplification. Preconditions include AMQP 1.0 with stream queues in use Attacker can attach a receiver with a filter (read permission) and publish messages with long property values (write permission). This issue is fixed in versions 4.2.7 and 4.3.1.",
  "id": "UBUNTU-CVE-2026-67240",
  "modified": "2026-09-24T00:00:00Z",
  "published": "2026-09-24T00:00:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-67240"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-67240"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-59c5-553c-57m2"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.2.7"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.3.1"
    }
  ],
  "related": [],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2026-67240"
  ]
}



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