Apache ActiveMQ 5.x before 5.13.0 does not restrict the classes that can be serialized in the broker, which allows remote attackers to execute arbitrary code via a crafted serialized Java Message Service (JMS) ObjectMessage object.
Severity
CVSS 3.0
9.8 critical
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS
38% chance of exploitation in the next 30 days; higher than 98% of CVEs (scores of 2026-10-31)