CVE-2025-66168

Published Mar 4, 2026

Last updated 9 days ago

CVSS medium 5.4

Overview

Description: Apache ActiveMQ does not properly validate the remaining length field which may lead to an overflow during the decoding of malformed packets. When this integer overflow occurs, ActiveMQ may incorrectly compute the total Remaining Length and subsequently misinterpret the payload as multiple MQTT control packets which makes the broker susceptible to unexpected behavior when interacting with non-compliant clients. This behavior violates the MQTT v3.1.1 specification, which restricts Remaining Length to a maximum of 4 bytes. The scenario occurs on established connections after the authentication process. Brokers that are not enabling mqtt transport connectors are not impacted. This issue affects Apache ActiveMQ: before 5.19.2, 6.0.0 to 6.1.8, and 6.2.0 Users are recommended to upgrade to version 5.19.2, 6.1.9, or 6.2.1, which fixes the issue.
Source: security@apache.org
NVD status: Analyzed
Products: activemq

Risk scores

CVSS 3.1

Type: Primary
Base score: 8.8
Impact score: 5.9
Exploitability score: 2.8
Vector string: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Severity: HIGH

Weaknesses

security@apache.org: CWE-190

Hype score: Not currently trending

Configurations

[
  {
    "nodes": [
      {
        "cpeMatch": [
          {
            "criteria": "cpe:2.3:a:apache:activemq:*:*:*:*:*:*:*:*",
            "matchCriteriaId": "8E187B7C-E072-439F-903C-5AD9227C5AE9",
            "versionEndExcluding": "5.19.2",
            "vulnerable": true
          },
          {
            "criteria": "cpe:2.3:a:apache:activemq:*:*:*:*:*:*:*:*",
            "matchCriteriaId": "61868905-AF68-4A48-B6C7-2B6E48D7FAA2",
            "versionEndIncluding": "6.1.8",
            "versionStartIncluding": "6.0.0",
            "vulnerable": true
          },
          {
            "criteria": "cpe:2.3:a:apache:activemq:6.2.0:*:*:*:*:*:*:*",
            "matchCriteriaId": "46AC8D1F-0ADA-402D-B600-8A37E0BF9062",
            "vulnerable": true
          }
        ],
        "negate": false,
        "operator": "OR"
      }
    ]
  }
]

References

Sources include official advisories and independent security research.

Overview

Risk scores

CVSS 3.1

Weaknesses

Social media

Configurations

Related CVEs

References