Atlassian Bamboo before 5.11.4.1 and 5.12.x before 5.12.3.1 does not properly restrict permitted deserialized classes, which allows remote attackers to execute arbitrary code via vectors related to XStream Serialization.
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
7.1% chance of exploitation in the next 30 days; higher than 94% of CVEs (scores of 2026-10-31)