{"cve":"CVE-2025-66168","nvd":{"published":"2026-03-04T09:15:54.757","modified":"2026-06-17T09:56:26.157","status":"Modified","description":"WARNING:\n\nUsers of 6.x should upgrade to 6.2.4 or later as the fix was missed in previous 6.x releases.\n\nSee the  following for more details:\n https://activemq.apache.org/security-advisories.data/CVE-2026-40046-announcement.txt \n https://www.cve.org/CVERecord?id=CVE-2026-40046 \n\n\n\nOriginal Report:\n\nApache 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.\n\nThis issue affects Apache ActiveMQ: before 5.19.2, 6.0.0 to 6.1.8, and 6.2.0\n\nUsers are recommended to upgrade to version 5.19.2, 6.1.9, or 6.2.1, which fixes the issue.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":8.8},"cwes":["CWE-190"],"references":["https://activemq.apache.org/security-advisories.data/CVE-2026-40046-announcement.txt","https://lists.apache.org/thread/13n8mkrb2jf2y6yyhpgrkmpqcm7djyto","https://www.cve.org/CVERecord?id=CVE-2026-40046","http://www.openwall.com/lists/oss-security/2026/03/03/5"],"products":["apache:activemq"],"source":"nvd","synced_at":"2026-10-19T22:24:17.937441719+00:00"},"epss":{"cve":"CVE-2025-66168","score":0.00872,"percentile":0.5889,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-c825-6ph3-4h84","url":"https://osv.dev/vulnerability/GHSA-c825-6ph3-4h84","summary":"Apache ActiveMQ is Vulnerable to Integer Overflow or Wraparound","modified":"2026-09-10T03:50:38.840053597Z","packages":[{"ecosystem":"Maven","name":"org.apache.activemq:apache-activemq","purl":"pkg:maven/org.apache.activemq/apache-activemq","ranges":["<5.19.2"],"fixed":["5.19.2"]},{"ecosystem":"Maven","name":"org.apache.activemq:apache-activemq","purl":"pkg:maven/org.apache.activemq/apache-activemq","ranges":[">=6.0.0 <6.1.9"],"fixed":["6.1.9"]},{"ecosystem":"Maven","name":"org.apache.activemq:apache-activemq","purl":"pkg:maven/org.apache.activemq/apache-activemq","ranges":[">=6.2.0 <6.2.1"],"fixed":["6.2.1"]},{"ecosystem":"Maven","name":"org.apache.activemq:activemq-all","purl":"pkg:maven/org.apache.activemq/activemq-all","ranges":["<5.19.2"],"fixed":["5.19.2"]},{"ecosystem":"Maven","name":"org.apache.activemq:activemq-all","purl":"pkg:maven/org.apache.activemq/activemq-all","ranges":[">=6.0.0 <6.1.9"],"fixed":["6.1.9"]},{"ecosystem":"Maven","name":"org.apache.activemq:activemq-all","purl":"pkg:maven/org.apache.activemq/activemq-all","ranges":[">=6.2.0 <6.2.1"],"fixed":["6.2.1"]},{"ecosystem":"Maven","name":"org.apache.activemq:activemq-mqtt","purl":"pkg:maven/org.apache.activemq/activemq-mqtt","ranges":["<5.19.2"],"fixed":["5.19.2"]},{"ecosystem":"Maven","name":"org.apache.activemq:activemq-mqtt","purl":"pkg:maven/org.apache.activemq/activemq-mqtt","ranges":[">=6.0.0 <6.1.9"],"fixed":["6.1.9"]},{"ecosystem":"Maven","name":"org.apache.activemq:activemq-mqtt","purl":"pkg:maven/org.apache.activemq/activemq-mqtt","ranges":[">=6.2.0 <6.2.1"],"fixed":["6.2.1"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}